This chapter discusses the epidemiology, prediction, prevention, and management of spontaneous preterm birth. Preterm birth is usually defined as delivery at any gestation before 37 completed weeks of pregnancy (<37⁺⁰ weeks, <259 days). The lower limit of preterm birth and upper limit of late spontaneous miscarriage are blurred as the limit of viability varies with differences in healthcare settings. This condition remains one of the biggest challenges facing obstetricians globally as a result of continuing high rates of morbidity and mortality. Spontaneous preterm birth is caused by a complex collection of pathophysiology with overlapping environmental interactions and behavioural influences that contribute to individual risk. Much debate exists regarding best prevention therapies and there remains a huge need for novel therapies and interventions for both prediction and prevention

Preterm birth (PTB) is a leading global cause of infant mortality. Risk factors include genetics, lifestyle choices, and infection. Understanding the mechanism of PTB could aid the development of novel approaches to prevent PTB. This study aimed to investigate the metabolic biomarkers of PTB in early pregnancy and the association of significant metabolites with participant genotypes. Maternal serum collected at 16 and 20 weeks of gestation, from women who previously experienced PTB (high-risk) and women who did not (low-risk controls), were analysed using 1H Nuclear Magnetic Resonance (NMR) metabolomics and genome-wide screening microarray. ANOVA and probabilistic neural network (PNN) modelling were performed on the spectral bins. Metabolomics genome-wide association (mGWAS) of the spectral bins and genotype data from the same participants was applied to determine potential metabolite-gene pathways. Phenylalanine, acetate and lactate metabolite differences between PTB cases and controls were obtained by ANOVA and PNN showed strong prediction at week 20 (AUC=0.89). MGWAS identified several metabolite bins with strong genetic associations. Cis-eQTL analysis highlighted TRAF1 (involved in the inflammatory pathway) local to a non-coding SNP associated with lactate at week 20 of gestation. MGWAS of a well-defined cohort of participants highlighted a lactate-TRAF1 relationship that could potentially contribute to PTB.

Despite much research effort, there is a paucity of conclusive evidence in the field of preterm birth prediction and prevention. The methods of monitoring and prevention strategies offered to women at risk vary considerably around the UK and depend on local maternity care provision. It is becoming increasingly recognised that this experience and knowledge, if captured on a larger scale, could be a utilized as a valuable source of evidence for others. The UK Preterm Clinical Network (UKPCN) was established with the aim of improving care and outcomes for women at risk of preterm birth through the sharing of a wealth of experience and knowledge, as well as the building of clinical and research collaboration. The design and development of a bespoke internet-based database was fundamental to achieving this aim. Following consultation with UKPCN members and agreement on a minimal dataset, the Preterm Clinical Network (PCN) Database was constructed to collect data from women at risk of preterm birth and their children. Information Governance and research ethics committee approval was given for the storage of historical as well as prospectively collected data. Collaborating centres have instant access to their own records, while use of pooled data is governed by the PCN Database Access Committee. Applications are welcomed from UKPCN members and other established research groups. The results of investigations using the data are expected to provide insights into the effectiveness of current surveillance practices and preterm birth interventions on a national and international scale, as well as the generation of ideas for innovation and research. To date, 31 sites are registered as Data Collection Centres, four of which are outside the UK. This paper outlines the aims of the PCN Database along with the development process undertaken from the initial idea to live launch.

Summary The role of the obstetrician is to help predict and prevent maternal/fetal infection/inflammation related to neonatal mortality and morbidity. Predictive studies have mainly focused on the high-risk phenotype. Currently, there is a scientific drive to analyse the genetic susceptibility of preterm birth (PTB). Studies of the combination of environmental and lifestyle risk factors with the known genotype may result in a better understanding of the causation of PTB. Predictive technical markers such as fibronectin, cervical length measurement and home uterine activity remain largely unproven. Current antenatal care has not achieved primary prevention of PTB. Tocolytics and antibiotics constitute the two key elements of secondary prevention. Tocolytics have a minimal benefit but should not be used to prolong an infected preterm pregnancy. The use of antibiotics in preterm premature rupture of membranes can prolong the pregnancy with a decrease in neonatal morbidity. Anti-inflammatory cytokines, cytokine inhibitors and soluble cytokine receptors are promising treatment options that could modulate the intra-amniotic inflammatory process.

The International Federation of Gynecology and Obstetrics (FIGO) has identified non communicable maternal diseases (NCDs) as a new focus area. NCDs and exposures as related to pregnancy complications and later impairment of maternal and offspring health will form the basis for action in the forthcoming years. This paper summarizes recent advances, centered on the use of first-trimester testing, as a window of opportunity to predict and prevent many pregnancy complications; and for potential future prevention of NCDs in mother and offspring. Recent results from a large-scale randomized control trial have provided definitive proof that effective screening for preterm preeclampsia (preterm-PE), requiring delivery before 37 weeks' gestation, can be achieved with a combined test of maternal factors and biomarkers at 11–13 weeks and that aspirin, given to high-risk women, is effective in reducing the risk of preterm-PE and the length of stay in neonatal intensive care unit. This is the first successful example to illustrate that pregnancy complications is predictable and preventable in early pregnancy. Similar prediction and prevention strategies are being developed for hyperglycemia in pregnancy and preterm birth, with the intention for longer lasting interventions leading to significant downstream impact in improving long-term health in both mothers and babies.

The increasing prevalence of gestational diabetes mellitus (GDM) is contributing to the rising global burden of type 2 diabetes (T2D) and intergenerational cycle of chronic metabolic disorders. Primary lifestyle interventions to manage GDM, including second trimester dietary and exercise guidance, have met with limited success due to late implementation, poor adherence and generic guidelines. In this study, we aimed to build a preconception-based GDM predictor to enable early intervention. We also assessed the associations of top predictors with GDM and adverse birth outcomes. Our evolutionary algorithm-based automated machine learning (AutoML) model was implemented with data from 222 Asian multi-ethnic women in a preconception cohort study, Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO). A stacked ensemble model with a gradient boosting classifier and linear support vector machine classifier (stochastic gradient descent training) was derived using genetic programming, achieving an excellent AUC of 0.93 based on four features (glycated hemoglobin A_1c (HbA_1c), mean arterial blood pressure, fasting insulin, triglycerides/HDL ratio). The results of multivariate logistic regression model showed that each 1 mmol/mol increase in preconception HbA_1c was positively associated with increased risks of GDM (p = 0.001, odds ratio (95% CI) 1.34 (1.13–1.60)) and preterm birth (p = 0.011, odds ratio 1.63 (1.12–2.38)). Optimal control of preconception HbA_1c may aid in preventing GDM and reducing the incidence of preterm birth. Our trained predictor has been deployed as a web application that can be easily employed in GDM intervention programs, prior to conception.

To summarize some recent major epidemiological changes, evidence-based interventions, shifting paradigms, and national initiatives targeting the prevention of preterm birth in the United States.Noteworthy epidemiological changes in preterm births include a shift from 40 to 39 weeks as the most common length of gestation for singleton births in the United States; significant jumps in late preterm births, which is the major contributor to increasing preterm rates: more multiple births with rates highest for non-Hispanic whites; dramatic increases in births to women of advanced maternal age; and substantial increases in cesarean births. Key paradigm shifts have also occurred such as considering most spontaneous preterm birth as a common complex disorder highlighting the importance of interactions of biological predispositions and environment; support for the fetal origins hypothesis requiring a life course perspective, including preconception health promotion to improve perinatal health and enhance equity; and a renewed focus on preventing recurrence. The March of Dimes National Prematurity Campaign, the National Institute of Child Health and Human Development leadership on late preterm birth, the 2006 Institute of Medicine's report on preterm birth, and passage of the Prematurity Research Expansion and Education for Mothers who Deliver Infants Early Bill with the resultant 2008 Surgeon General's Conference underscore the national resolve to prevent preterm births.Despite the complex changing environment of perinatal care, shrinking resources and higher risk pregnancies, innovative strategies, expanded, interdisciplinary partnerships, a focus on perinatal quality initiatives, more evidence-based interventions, tools to better predict preterm labor/birth, dissemination of effective community-based programs, a commitment to enhance equity, promoting preconception health, translation of research findings from the bench to bedside to curbside, effective continuing education for busy clinicians and culturally sensitive, health literacy appropriate patient education materials can collectively help to reverse the increasing rates of preterm births.

To summarize the current knowledge about the care of pregnant women after fertility-preserving operations for cervical cancer. Review article. Department of Gynecology and Obstetrics, 1st Faculty of Medicine, Charles University and General University Hospital, Prague. Search of published literature on a given topic using the PubMed database. Pregnant women after fertility-sparing surgery for cervical cancer can benefit from screening and treatment for asymptomatic bacteriuria, cervical incompetence screening, and progressive cervical shortening by transvaginal ultrasonography. Tests to determine the presence of biomarkers of preterm birth in cervicovaginal fluid improve the prediction of preterm birth. Vaginal progesterone supplementation should be the primary prevention of preterm birth in all women after trachelectomy. Women with a history of preterm birth or late abortion may benefit from cerclage. The preferred mode of delivery is the cesarean section after 37 weeks of gestation. Due to the lack of data, pregnancy management in women who have undergone fertility-sparing surgery for early cervical cancer is inconsistent. An increasing number of pregnancies after fertility-sparing surgery will likely prompt clinical research in this field.

Objective To describe pregnancy intention and contraceptive use among women with a recent delivery that occurred at 35 weeks gestation or fewer and who were enrolled in a large‐scale randomized control trial. Design In this descriptive study we used data from assessments conducted at 6 months postpartum as part of a randomized controlled clinical trial, the Philadelphia Collaborative Preterm Prevention Project (PCPPP). Participants and Setting Participants were recruited following a preterm birth (PTB) in one of the 12 urban birth hospitals. All women enrolled in PCPPP, who completed their 6‐month postpartum assessment, and who were sexually active at the time of that assessment (n = 566), were included in the analysis. Methods Data were collected during face‐to‐face interviews. Study questionnaires included questions about participants' plans for the timing of subsequent pregnancies, contraceptive behaviors, and other health variables. Results Nearly all of the participants (90.1%, n = 509) reported they did not want to get pregnant within one year of the index PTB. However, more than one half of these women (54.6%) reported contraceptive practices of low or moderate effectiveness. Most predictive of intending another pregnancy within the year was the death of the index PTB infant (odds ratio [OR]= 18.2,95% confidence interval [CI] [8.9, 37.0]). Conclusions Discordant pregnancy intention and contraceptive use were reported among this group of mothers of PTB infants who are at particularly high risk for a poor outcome of any subsequent pregnancy. The findings highlight the need for further investigation of the causes, correlates, and consequences of discordant pregnancy intentions and contraceptive practices.

Recently the March of Dimes and the International Federation of Gynecology and Obstetrics Working Group on Preterm Birth released its findings from an extensive cross-country individual patient data analysis of 4.1 million singleton births in five high-income, very high human development index countries. The specific contributions of 21 risk factors for both spontaneous and health care provider-initiated preterm birth were assessed to better understand how these vary among the countries selected for intensive study. We also wished to evaluate whether currently used clinical interventions to prevent preterm birth are associated with lower rates of preterm delivery. Individual and population-attributable preterm birth risks were determined and an assessment made to identify any contribution to cross-country differences. With this massive data set it was possible to assess the ability to predict preterm birth given various sets of known risk factors. It was also possible to estimate the potential effects of successful interventions to reduce preterm birth in relation to advances in the research, health care policy, and clinical practice sectors. In this article we summarize the seven most important findings from these analyses. Clearly there is a paucity of explicit and currently identifiable factors that are amenable to intervention with current clinical practice or changes in public health policy. Thus, we see an urgent and critically important need for research efforts to elucidate the underlying biological causes of spontaneous preterm birth. The need for new innovative and effective interventions to successfully pursue progress toward effective preterm birth reduction has never been more apparent.

Despite scientific advances, efforts to prevent preterm birth can be disappointing. Obstetric care must focus on strategies to improve the outcome of preterm infants. The major goal is to delay preterm birth long enough to allow the transfer of women about to deliver preterm to a facility with a neonatal intensive care unit and to administer corticosteroids to enhance fetal lung maturation. A prerequisite for the success of this strategy is the reliable identification of women who will give birth preterm. Although symptoms of preterm labour strongly suggest preterm birth, contractions-even if combined with cervical effacement and dilation-do not reliably predict preterm birth. The diagnosis of true preterm labour that will eventually lead to preterm birth has been facilitated by the use of transvaginal cervical ultrasonography and by the detection of fetal fibronectin (FFN) in cervicovaginal secretions. The main clinical value of these tests is that preterm birth is very unlikely if the results of both tests are negative. This may help to avoid unnecessary transfer, hospitalisation and treatment of women with false preterm labour. The detection of phosphorylated insulin-like growth factor binding protein-1 in cervicovaginal secretions, or elevated levels of inflammatory markers, like interleukin-6, interleukin-8 and tumour necrosis factor-alpha (TNF-alpha), also predict preterm birth in symptomatic women. These markers, however, are not routinely used to predict preterm birth in women with symptoms of preterm labour.

Background-The management of patent ductus arteriosus in preterm neonates continues to be a topic of discussion and controversy. Prolonged ductal patency in preterm neonates has been associated with significant short and long-term morbidities and with increased mortality however, the policy of routine treatment of all during the neonatal period has failed to show significant improvement in the long-term outcome. Echocardiography has emerged as a promising modality to screen newborns at risk of adverse effects of ductal shunting. This helps in identifying PDAs that require treatment to ultimately prevent unnecessary therapy or delay of necessary therapy. There is a multitude of studies that have evaluated a large number of echocardiographic markers for their predictive utility but only a few have included all ductal markers together in a single study. The reported sensitivity (26-100%) and specificity (6-100%) of echocardiographic markers vary over a wide range. Thus, this study was planned to assess the predictive utility of all available ductal markers and their added advantage of having all over few ones in clinically apparent PDA in preterm VLBW newborns.Methods-It was an observational prospective study conducted in tertiary care NICU at Lady Hardinge Medical College, Delhi. Fifty preterms very low birth weight (VLBW) newborns underwent four sequential Echo scans within the first 72 hrs; the first scan within 12 hours, thereafter at 24 hrs,48 hrs, and 72 hrs of age and were monitored clinically for the signs of PDA up to two weeks of life or discharge whichever comes later.Results-The Ductal diameter, pulsatile ductal flow pattern, Left pulmonary artery (LPA) velocity, Left atrial to aortic width (La/Ao) ratio, Left atrial volume index (LAVI), Left ventricle to aortic width (Lv/Ao) ratio, E/A ratio and Left ventricular output/superior vena cava (LVO/SVC) flow ratio predicted clinically apparent PDA during first 72 hours of life.Conclusion- This study provides insights into the predictive utility of other ductal echo markers along with the routinely measured conventional ones during the first 72 hours of life in preterm VLBW newborns.

Background The management of patent ductus arteriosus in preterm neonates continues to be a topic of discussion and controversy. Prolonged ductal patency in preterm neonates has been associated with significant short and long term morbidities and with increased mortality however, policy of routine treatment of all during neonatal period has failed to show significant improvement in long term outcome. Echocardiography has emerged as a promising modality to screen the newborns at risk of adverse effects of ductal shunting. This helps in identifying PDAs that require treatment to ultimately prevent unnecessary therapy or delay of necessary therapy. There are multitude of studies that have evaluated large number of echocardiographic markers for their predictive utility but only few have included all ductal markers together in a single study. The reported sensitivity (26-100%) and specificity (6-100%) of echocardiographic markers vary over a wide range. Thus, this study was planned with an aim to assess the predictive utility of all available ductal markers and their added advantage of having all over few ones in clinically apparent PDA in preterm VLBW newborns.Methods It was an observational prospective study conducted in tertiary care NICU at Lady Hardinge Medical College, Delhi. Fifty preterm very low birth weight (VLBW) newborns underwent four sequential Echo scans within first 72 hrs; first scan within 12 hours then at 24 hrs ,48 hrs and 72 hrs of age and were monitored clinically for the signs of PDA up to two weeks of life or discharge whichever comes later.Results The Ductal diameter, pulsatile ductal flow pattern, Left pulmonary artery (LPA) velocity, Left atrial to aortic width (La/Ao) ratio, Left atrial volume index (LAVI), Left ventricle to aortic width (Lv/Ao) ratio, E/A ratio and Left ventricular output/superior vena caval (LVO/SVC) flow ratio predicted clinically apparent PDA during first 72 hours of life.Conclusion This study provides insights into the predictive utility of other ductal echo markers along with the routinely measured conventional ones during first 72 hours of life in preterm VLBW newborns.

Preterm births (PTBs), defined as births before 37 weeks of gestation account for the majority of deaths in the newborn period. Prediction and prevention of PTB is challenging. A history of preterm labour or second trimester losses and accurate measurement of cervical length help to identify women who would benefit from progesterone and cerclage. Fibronectin estimation in the cervicovaginal secretions of a symptomatic woman with an undilated cervix can predict PTB within 10 days of testing. Antibiotics should be given to women with preterm prelabour rupture of membranes but tocolysis has a limited role in the management of preterm labour. Antenatal corticosteroids to prevent complications in the neonate should be given only when gestational age assessment is accurate PTB is considered imminent, maternal infection and the preterm newborn can receive adequate care. Magnesium sulphate for fetal neuroprotection should be given when delivery is imminent. After birth, most babies respond to simple interventions essential newborn care, basic care for feeding support, infections and breathing difficulties. Newborns weighing 2000 g or less, benefit from KMC. Babies, who are clinically unstable or cannot be given KMC may be nursed in an incubator or under a radiant warmer. Treatment modalities include oxygen therapy, CPAP, surfactant and assisted ventilation.

Preterm birth incidence has risen globally and remains a major cause of neonatal mortality despite improved survival. Demand and cost of initial hospitalization has also increased. This study assessed the cost of preterm birth during initial hospitalization from care provider perspective in neonatal intensive care units (NICU) of two hospitals in the state of Kedah, Malaysia. It utilized universal sampling and prospectively followed up preterm infants till discharge. Care provider cost was assessed using mixed method of top down approach and activity based costing. A total of 112 preterm infants were recruited from intensive care (93 infants) and minimal care (19 infants) units. Majority were from the moderate (23%) and late (36%) preterm groups followed by very preterm (32%) and extreme preterm (9%). Median cost per infant increased with level of care and degree of prematurity. Cost was dominated by overhead (fixed) costs for general (hospital), intermediate (clinical support services) and final (NICU) cost centers where it constituted at least three quarters of admission cost per infant while the remainder was consumables (variable) cost. Breakdown of overhead cost showed NICU specific overhead contributing at least two thirds of admission cost per infant. Personnel salary made up three quarters of NICU specific overhead. Laboratory investigation was the cost driver for consumables. Gender, birth weight and length of stay were significant factors and cost prediction was developed with these variables. This study demonstrated the inverse relation between resource utilization, cost and prematurity and identified personnel salary as the cost driver. Cost estimates and prediction provide in-depth understanding of provider cost and are applicable for further economic evaluations. Since gender is non-modifiable and reducing LOS alone is not effective, birth weight as a cost predictive factor in this study can be addressed through measures to prevent or delay preterm birth.

Adverse obstetric outcomes, such as preeclampsia, preterm birth, gestational diabetes, and fetal growth restriction, are poorly predicted by maternal history and risk factors alone, especially in nulliparae. The ability to predict these outcomes from the first trimester would allow for the early initiation of prophylactic therapies, institution of an appropriate model and location of care, and recruitment of a truly “high risk” population to clinical trials of interventions to prevent or ameliorate these conditions. To this end, development of adequately sensitive and specific predictive tests for these outcomes has become a significant focus of perinatal research. This paper reviews the biomarkers involved in these multiparametric tests and also outlines the performance of these tests and issues regarding their introduction into clinical practice.

Objective The objective of this study was to create three point-of-care predictive models for very preterm birth using variables available at three different time points: prior to pregnancy, at the end of the first trimester, and mid-pregnancy. Study Design This is a retrospective cohort study of 359,396 Ohio Medicaid mothers from 2008 to 2015. The last baby for each mother was included in the final dataset. Births prior to 22 weeks were excluded. Multivariable logistic regression was used to create three models. These models were validated on a cohort that was set aside and not part of the model development. The main outcome measure was birth prior to 32 weeks. Results The final dataset contained 359,396 live births with 6,516 (1.81%) very preterm births. All models had excellent calibration. Goodness-of-fit tests suggested strong agreement between the probabilities estimated by the model and the actual outcome experience in the data. The mid-pregnancy model had acceptable discrimination with an area under the receiver operator characteristic curve of approximately 0.75 in both the developmental and validation datasets. Conclusion Using data from a large Ohio Medicaid cohort we developed point-of-care predictive models that could be used before pregnancy, after the first trimester, and in mid-pregnancy to estimate the probability of very preterm birth. Future work is needed to determine how the calculator could be used to target interventions to prevent very preterm birth. Key Points The work was conceived and designed by S.G.G and P.T.G., S.L., G.N., and C.L.H. Data analysis and interpretation were performed by S.L., G.N., and J.B. and G.P.. The article was drafted jointly by C.L.H., G.N., S.L., S.G.G, and P.T.G. All authors reviewed and critically revised the article. All authors approved the final version. IRB approval for all aspects of this study was obtained through the Ohio Department of Health IRB (Protocol numbers 2016–41, approved July 26, 2016 and 2017–39, date of initial approval July 25, 17) and the Ohio State University IRB (protocol number 2016B02291, date of initial approval September 25, 2016). ^* Presently an independent consultant. Received: 28 February 2020 Accepted: 13 June 2020 Publication Date: 23 August 2020 (online) © 2020. Thieme. All rights reserved. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Preterm birth remains a leading cause of morbidity and mortality during the perinatal and neonatal periods. Now affecting approximately 1 in 10 births in the United States, preterm birth often occurs spontaneously and without a clear etiology. Careful assessment of risk factors, however, identifies vulnerable women allowing targeted interventions such as progestogen therapy and cerclage. This article is intended to highlight preterm birth risk factors and current predictive and preventive strategies for midwives, nurse practitioners, clinical nurse specialists, and perinatal nurses.

Preterm birth is the most important cause of neonatal mortality and morbidity worldwide. In this review, we review potential risk factors associated with preterm birth and the subsequent management to prevent preterm birth in low and high risk women with a singleton or multiple pregnancy. A history of preterm birth is considered the most important risk factor for preterm birth in subsequent pregnancy. General risk factors with a much lower impact include ethnicity, low socio-economic status, maternal weight, smoking, and periodontal status. Pregnancy-related characteristics, including bacterial vaginosis and asymptomatic bacteriuria, appear to be of limited value in the prediction of preterm birth. By contrast, a mid-pregnancy cervical length measurement is independently associated with preterm birth and could be used to identify women at risk of a premature delivery. A fetal fibronectin test may be of additional value in the prediction of preterm birth. The most effective methods to prevent preterm birth depend on the obstetric history, which makes the identification of women at risk of preterm birth an important task for clinical care provider

Background: Preterm delivery (before 37 weeks of gestation) is the single most important contributor to neonatal death and morbidity, with lifelong repercussions. However, the majority of women who present with preterm labour (PTL) symptoms do not deliver imminently. Accurate prediction of PTL is needed in order ensure correct management of those most at risk of preterm birth (PTB) and to prevent the maternal and fetal risks incurred by unnecessary interventions given to the majority. The QUantitative Innovation in Predicting Preterm birth (QUIPP) app aims to support clinical decision-making about women in threatened preterm labour (TPTL) by combining quantitative fetal fibronectin (qfFN) values, cervical length (CL), and significant PTB risk factors to create an individualised percentage risk of delivery. Methods and findings: EQUIPTT was a multi-centre cluster randomised controlled trial (RCT) involving 13 maternity units in South and Eastern England (United Kingdom) between March 2018 and February 2019. Pregnant women (n = 1,872) between 23⁺⁰ and 34⁺⁶ weeks’ gestation with symptoms of PTL in the analysis period were assigned to either the intervention (762) or control (1,111). The mean age of the study population was 30.2 (+/− SD 5.93). A total of 56.0% were white, 19.6% were black, 14.2% were Asian, and 10.2% were of other ethnicities. The intervention was the use of the QUiPP app with admission, antenatal corticosteroids (ACSs), and transfer advised for women with a QUiPP risk of delivery >5% within 7 days. Control sites continued with their conventional management of TPTL. Unnecessary management for TPTL was a composite primary outcome defined by the sum of unnecessary admission decisions (admitted and delivery interval >7 days or not admitted and delivery interval ≤7 days) and the number of unnecessary in utero transfer (IUT) decisions/actions (IUT that occurred or were attempted >7 days prior to delivery) and ex utero transfers (EUTs) that should have been in utero (attempted and not attempted). Unnecessary management of TPTL was 11.3% (84/741) at the intervention sites versus 11.5% (126/1094) at control sites (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.66–1.42, p = 0.883). Control sites frequently used qfFN and did not follow UK national guidance, which recommends routine treatment below 30 weeks without testing. Unnecessary management largely consisted of unnecessary admissions which were similar at intervention and control sites (10.7% versus 10.8% of all visits). In terms of adverse outcomes for women in TPTL <36 weeks, 4 women from the intervention sites and 12 from the control sites did not receive recommended management. If the QUiPP percentage risk was used as per protocol, unnecessary management would have been 7.4% (43/578) versus 9.9% (134/1,351) (OR 0.72, 95% CI 0.45–1.16). Our external validation of the QUiPP app confirmed that it was highly predictive of delivery in 7 days; receiver operating curve area was 0.90 (95% CI 0.85–0.95) for symptomatic women. Study limitations included a lack of compliance with national guidance at the control sites and difficulties in implementation of the QUiPP app. Conclusions: This cluster randomised trial did not demonstrate that the use of the QUiPP app reduced unnecessary management of TPTL compared to current management but would safely improve the management recommended by the National Institute for Health and Care Excellence (NICE). Interpretation of qfFN, with or without the QUiPP app, is a safe and accurate method for identifying women most likely to benefit from PTL interventions. Trial registration: ISRCTN Registry ISRCTN17846337.

Preterm birth (PTB) remains a major obstetric healthcare problem and a significant contributor to perinatal morbidity, mortality, and long-term disability. Over the past few decades, the perinatal outcomes of preterm neonates have improved markedly through research and advances in neonatal care, whereas rates of spontaneous PTB have essentially remained static. However, research into causal pathways and new diagnostic and treatment modalities is now bearing fruit and translational initiatives are beginning to impact upon PTB rates. Successful PTB prevention requires a multifaceted approach, combining public health and educational programs, lifestyle modification, access to/optimisation of obstetric healthcare, effective prediction and diagnostic modalities, and the application of effective, targeted interventions. Progress has been made in some of these areas, although there remain areas of controversy and uncertainty. Attention is now being directed to areas where greater gains can be achieved. In this mini-review, we will briefly and selectively review a range of PTB prevention strategies and initiatives where progress has been made and where exciting opportunities await exploitation, evaluation, and implementation.

Preterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice. We analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors. Previous preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6–6.0 and 2.8–5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25–50% and 11–16% of excess population attributable risk, respectively (p<0.001). The importance of nulliparity and male sex on population attributable risk was driven by high prevalence despite low odds ratios for individual women. More than 65% of the total aggregated risk of preterm birth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying mechanisms of preterm birth and, hence, therapeutic intervention. Surprisingly, variation in prevalence of known risk factors accounted for less than 35% of the difference in preterm birth rates between countries. Known risk factors had an area under the curve of less than 0.7 in ROC analysis of preterm birth prediction within countries. These data suggest that other influences, as yet unidentified, are involved in preterm birth. Further research into biological mechanisms is warranted. We have quantified the causes of variation in preterm birth rates among countries with very high human development index. The paucity of explicit and currently identified factors amenable to intervention illustrates the limited impact of changes possible through current clinical practice and policy interventions. Our research highlights the urgent need for research into underlying biological causes of preterm birth, which alone are likely to lead to innovative and efficacious interventions.

Objective Preterm birth is a leading cause of perinatal morbidity and mortality. Prevention strategies rarely focus on preconception care. We sought to create a preconception nomogram that identifies nonpregnant women at highest risk for preterm birth using the Pregnancy Risk Assessment Monitoring System (PRAMS) surveillance data. Methods We used PRAMS data from 2004 to 2009. The odds ratios (ORs) of preterm birth for each preconception variable was estimated and adjusted analyses were conducted. We created a validated nomogram predicting the probability of preterm birth using multivariate logistic regression coefficients. Results 192,208 cases met inclusion criteria. Demographic/maternal health characteristics and associations with preterm birth and ORs are reported. After validation, we identified the following significant predictors of preterm birth: prior history of preterm birth or low birth weight baby, prior spontaneous or elective abortion, maternal diabetes prior to conception, maternal race (e.g., non-Hispanic black), intention to get pregnant prior to conception (i.e., did not want or wanted it sooner), and smoking prior to conception (p< 0.05). Overall, our preconception preterm risk model correctly classified 76.1 % of preterm cases with a negative predictive value (NPV) of 76.7 %. A nomogram using a 0–100 scale illustrates our final preconception model for predicting preterm birth. Conclusion This preconception nomogram can be used by clinicians in multiple settings as a tool to help predict a woman’s individual preterm birth risk and to triage high-risk non-pregnant women to preconception care. Future studies are needed to validate the nomogram in a clinical setting.

After several decades of research we now have evidence that at least six interventions are suitable for immediate use in contemporary clinical practice within high-resource settings and can be expected to safely reduce the rate of preterm birth. These interventions involve strategies to prevent non-medically indicated late preterm birth; use of maternal progesterone supplementation; surgical closure of the cervix with cerclage; prevention of exposure of pregnant women to cigarette smoke; judicious use of fertility treatments; and dedicated preterm birth prevention clinics. Quantification of the extent of success is difficult to predict and will be dependent on other clinical, cultural, societal and economic factors operating in each environment. Further success can be anticipated in the coming years as other research discoveries are translated into clinical practice, including new approaches to treating intra-uterine infection, improvements in maternal nutrition and lifestyle modifications to ameliorate maternal stress. The widespread use of human papillomavirus (HPV) vaccination in girls and young women will decrease the need for surgical interventions on the cervix and can be expected to further reduce the risk of early birth. Together, this array of clinical interventions, each based on a substantial body of evidence, is likely to reduce rates of preterm birth and prevent death and disability in large numbers of children. The process begins with an acceptance that early birth is not an inevitable and natural feature of human reproduction. Preventative strategies are now available and need to be applied. The best outcomes may come from developing integrated strategies designed specifically for each health care environment.

Context: Preterm birth accounts for significant neonatal mortality and morbidity as well as substantial health costs. As our understanding of aetiology and risk factors for preterm birth increases, predictive tools and prophylactic interventions have been developed to improve maternal and fetal outcomes. These are effective, but require surveillance of asymptomatic high-risk women, as well as ultrasound and surgical expertise. This has led to the development of preterm birth surveillance clinics (PSCs), which pool these resources together and have changed the focus of care from reactive to predictive and preventative management. Methods: A literature review of the evidence surrounding the predictive tests (cervical length, fetal fibronectin, Actim Partus, Partosure) and prophylactic interventions (cerclage, progesterone, Arabin pessary, antibiotics, and steroids) for preterm birth to understand what preterm birth surveillance clinics do and how effective they are. Results: Measuring cervical length and fetal fibronectin levels are two of the most accurate predictive tests preterm birth, especially when used in combination. Other predictive tools like Actim Partus and Partosure are effective for symptomatic women, but their role in surveillance of asymptomatic women is unclear. Cervical cerclage is effective in reducing preterm birth in women with previous losses, but the role of progesterone and pessaries remains debated. Steroids remain one of the most effective antenatal intervention, but they need to be administered within a tight timeframe in order to confer maximal benefit. The role of PSCs in predicting the timing of birth and targeting women at highest risk to appropriate interventions is therefore crucial in optimizing care and improving outcomes. Conclusions: Nearly every step of management is still debated although many have a strong evidence-base and effective interventions do exist. The challenge is finding the optimal management pathway, and details of which populations benefit from which interventions need to be evaluated. While evidence continues to be collated, the poor outcomes of preterm birth and the multiple options available to reduce them justify preterm birth surveillance clinics being resourced. Keywords: Preterm Birth; Predictive; Fetal Fibronectin; Cervical Length; Cervical Cerclage

Reducing preterm birth is a priority for Maternity and Children’s services. In the recent UK Department of Health publication ‘Safer Maternity Care’ the Secretary of State for Health aimed to achieve the national maternity safety ambition by pledging to reduce the rate of preterm birth from 8% to 6%. It was proposed that specialist preterm birth services should be established in the UK in order to achieve this aim. In response the Preterm Clinical Network has written Commissioning Guidance aimed to establish best practice pathways and agreed models of care to reduce variation nationally. They have been developed by clinical experts in the field, from within the UK, to provide recommendations for commissioning groups and to recommend pathways to organisations with the aim of reducing the incidence of preterm birth. Three key areas of care provision are focused on: prediction, prevention and preparation of women at high risk of PTB. This Expert Opinion, will summarise the Commissioning Guidance.

Significance. The need for resources in the health care system is constantly increasing. Identification of manageable factors to improve quality of care delivery to extremely (very) preterm newborns will make it possible to improve care delivery. Regular monitoring of the preterm birth indicator with an assessment of its outcomes and identification of manageable factors is extremely important and relevant in terms of its systematic nature for the region, country and the world as a whole. The purpose of this study is to identify manageable factors to improve quality of care provided to babies with very low weight at birth born before 32 weeks of gestation. Material and methods. A three-stage study on features of care delivery to newborns born before 32 weeks of gestation (stage 1 - 2012, stage 2 - 2015 and stage 3 - 2019) was conducted using the typical sampling method. Results. The study has identified the following manageable risk factors: peculiar adaptation and physical development of preterm babies (born before 32 weeks of gestation) due to various causes of preterm delivery. The study has also confirmed that the main causes of preterm birth before 32 weeks of gestation include hypoxia and infection, with hypoxia prevailing, which directly affects the physical development and adaptation of preterm newborns. There is a reliable relationship between the earliest delivery, as well as pathological nature of early adaptation of newborns, determined by the Apgar scale, and the most unfavorable outcomes in children born to women with infection. Conclusion. The study has determined the structure of causes of preterm delivery and characteristics of early adaptation of newborns, which can serve basis for preventing pathological conditions and predicting status of very preterm newborns.Implementation of organizational activities aimed at early detection and prevention of manageable risk factors with their subsequent monitoring will make it possible to strengthen positive dynamics in the rate of decline in negative demographic indicators. Scope of application. The results of the study can be used by specialists in health care organization, heads of medical organizations, specialists in gynecology and obstetrics and neonatology to improve quality of care delivery to extremely (very) preterm newborns. Keywords: manageable factors; morbidity indicators; mortality indicators; preterm newborns; causes of premature labor

Preterm birth (PTB) remains the most serious complication in obstetrics and a substantial excess burden in US healthcare economics. The etiology of PTB is complex and likely has multiple physiological pathways. Unfortunately, current antenatal care screening methods have not been successful in predicting and, eventually, preventing PTB. Although treatments such as progesterone, cerclage and pessary are available for patients with historical risk factors and shortened cervix, these treatments are not universally efficacious. Antenatal care is in great need of new prediction and prevention strategies. The role of more global methods of screening and treatment is still undefined. Most women with clinical risk factors will not deliver early, and aggressive interventions in large segments of the population may not be warranted or cost effective. Furthermore, over half of women who experience PTB have no historical risk factors. Even second-trimester cervical length (CL) has only modest ability to predict which women will experience PTB. There is thus a clear need to identify biomarkers that provide quantitative, individualized assessment of risk early in pregnancy that is specific for each individual woman. The ideal biomarkers would be indicative of the pathway leading to PTB, require no special testing equipment, have a low false positive and negative rate, and offer early identification, allowing adequate time to intervene. We need an aggressive and comprehensive approach to see a dramatic reduction in rates of preterm delivery in the U.S

Objective The study aimed to determine if a program of mid-trimester serum proteomics screening of women at low risk for spontaneous preterm birth (sPTB) and the use of a PTB risk-reduction protocol in those whose results indicated an increased risk of sPTB would reduce the likelihood of sPTB and its sequelae. Study Design Prospective comparison of birth outcomes in singleton pregnancies with mid-trimester cervical length ≥2.5 cm and at otherwise low risk for sPTB randomized to undergo or not undergo mid-trimester serum proteomics screening for increased risk of sPTB (NCT 03530332). Screen-positive women were offered a group of interventions aimed at reducing the risk of spontaneous PTB. The primary outcome was the rate of sPTB <37 weeks, and secondary outcomes were gestational age at delivery, total length of neonatal stay, and NICU length of stay (LOS). Unscreened and screen-negative women received standard care. The adaptive study design targeted a sample size of 3,000 to 10,000 women to detect a reduction in sPTB from 6.4 to 4.7%. Due to limited resources, the trial was stopped early prior to data unblinding. Results A total of 1,191 women were randomized. Screened and unscreened women were demographically similar. sPTB <37 weeks occurred in 2.7% of screened women and 3.5% of controls (p = 0.41). In the screened compared with the unscreened group, there were no between-group differences in the gestational age at delivery, total length of neonatal stay, and NICU LOS. However, the NICU LOS among infants admitted for sPTB was significantly shorter (median = 6.8 days, interquartile range [IQR]: 1.8–8.0 vs. 45.5 days, IQR: 34.6–79.0; p = 0.005). Conclusion Mid-trimester serum proteomics screening of women at low risk for sPTB and the use of a sPTB risk-reduction protocol in screen-positive patients did not significantly reduce the rate of sPTB compared with women not screened, though the trial was underpowered thus limiting the interpretation of negative findings. Infants in the screened group had a significantly shorter NICU LOS, a difference likely due to a reduced number of infants in the screened group that delivered <35 weeks. Key Points

To assess the performance of the PAMG-1 and fFN tests using real-world data for the prediction of spontaneous preterm delivery (sPTD) in patients presenting to an emergency obstetrical unit with threatened preterm labour (PTL) by conducting a retrospective audit of patient medical records over two different one-year time periods during which either fFN or PAMG-1 was used as the standard of care biochemical test. A retrospective cohort study chart review of women with threatened PTL electronic medical records (EMR) from a Level III maternity hospital was conducted for two periods of one year each: (1) the “Baseline” time period, during which the qualitative fFN test with a cutoff of 50 ng/ml was used as standard of care biochemical test for the risk assessment of preterm delivery, and (2) the “Comparative” time period, during which the PAMG-1 test with a cutoff of 1 ng/mL was used as the standard of care biomarker test. Patients with singleton gestations between 24⁺⁰ to 34⁺⁶ weeks of gestation with symptoms of early preterm labour, clinically intact membranes, and cervical dilation 4 times more reliable than a positive fFN test in predicting imminent sPTD. Fewer positive biomarker test results that are more reliable is associated with a reduction in unnecessary admissions, avoidable treatments, and preventable use of hospital resources.

Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality. Women with previous prenatal loss are at higher risk of preterm birth. A specialist antenatal clinic is considered as one approach to improve maternity and pregnancy outcomes. A systematic review of quantitative, qualitative and mixed method studies conducted on women at high risk of preterm birth (PTB). The review primary outcomes were to report on the specialist antenatal clinics effect in preventing or reducing preterm birth, perinatal mortality and morbidity and women’s perceptions and experiences of a specialist clinic whether compared or not compared with standard antenatal care. Other secondary maternal, infant and economic outcomes were also determined. A comprehensive search strategy was carried out in English within electronic databases as far back as 1980. The reviewers selected studies, assessed the quality, and extracted data independently. Results were summarized and tabulated. Eleven studies fully met the review inclusion criteria, ten were quantitative design studies and only one was a qualitative design study. No mixed method design study was included in the review. All were published after 1989, seven were conducted in the USA and four in the UK. Results from five good to low quality randomised controlled trials (RCTs), all conducted before 1990, did not illustrate the efficacy of the clinic in reducing preterm birth. Whereas results from more recent low quality cohort studies showed some positive neonatal outcomes. Themes from one good quality qualitative study reflected on the emotional and psychological need to reduce anxiety and stress of women referred to such a clinic. Women expressed their negative emotional responses at being labelled as high risk and positive responses to being assessed and treated in the clinic. Women also reported that their partners were struggling to cope emotionally. Findings from this review were mixed. Evidence from cohort studies indicated a specialist clinic may be a means of predicting or preventing preterm birth. Testing this in a randomised controlled trial is desirable, though may be hard to achieve due to the growing focus of such clinics on managing women at high risk of preterm birth. Ongoing research has to recognize women’s experiences and perceptions of such a clinic. Further clarification of the optimal referral route and a clear and standardized management and cost economic evaluation plan are also required. Fathers support and experience of PTB clinics should also be included in further research.

Moderate and late preterm births account for the majority of preterm babies. The common perception that birth at 32-36 weeks' gestation carries few risks is now being challenged, as these babies have increased risk of neonatal mortality and morbidity. However, spontaneous labour at this gestation frequently has no specific, easily identifiable precursor, although preterm birth per se has a number of epidemiological and clinical associations. Prediction and prevention of preterm birth is currently largely aimed at identifying women at high risk such as those with previous preterm birth, and targeting intervention at this group. Both cervical length assessment and fibronectin testing permit some modification of the likelihood of preterm birth in this group. Progesterone treatment for the prevention of preterm birth is currently being researched widely, and appears a potentially promising strategy. Babies born at 32-36 weeks' gestation need careful monitoring in labour, with modification of intervention in labour due to their prematurity.

Preterm birth is the main cause of perinatal mortality and morbidity and can be very costly to the healthcare system. Although improvements in neonatal care have led to higher survival of very premature infants, there is a need for the development of a sensitive method with which to identify women at high risk of preterm delivery and find an effective strategy for the prevention of preterm labor.¹ Considering the increased incidence of preterm birth, it has become more important now to be able to early diagnose this problem. The measurement of cervical length to predict the risk of preterm birth can be extremely useful in diagnosing this condition. The use of transvaginal ultrasound in measuring cervical length is safe, reliable and well accepted by women.² The use of vaginal progesterone has shown to be effective in the prevention of preterm delivery in women with short cervix. Tocolytics are used to delay labor for a minimum of 24 to 48 hours³ for up to 1 week but they have not shown to improve neonatal outcomes and most have undesirable side effects. Steroids can assist with fetal lung maturity when the diagnosis of preterm labor is made,³ they can be used unnecessarily when preterm labor is misdiagnosed. The measurement of cervical length can also be helpful in patients with preterm premature rupture of membrane and in patients with the presence of amniotic fluid (AF) sluge.⁴ Therefore, performing cervical length measurements in all pregnant women and use it as a screening tool at around 20 weeks of pregnancy to identify patients at high risk of preterm labor can assist with true diagnosis. There is a great expectation from cervical assessment and subsequent addition of progesterone to reduce preterm birth and have better neonatal outcomes. The aim of this review is to bring forward evidence that highlights the importance of performing cervical length measurement in midpregnancy in all pregnant women to predict the risk of preterm birth. Medline, PubMed, MD Consult and Science Direct were searched using the terms cervical length measurement, ‘preterm delivery’, ‘amniotic fluid sludge’ and ‘treatment for preterm birth’. How to cite this article: Ahmed B, Hasnani Z. Cervical Length Measurement in Obstetrics: From Academic Luxury to Clinical Practice. Donald School J Ultrasound Obstet Gynecol 2012;6(1):93-96.

Education of communities about preterm birth is essential because preterm birth is a major perinatal health problem, contributing 60–80% of the perinatal mortality in the United States. Preterm birth impacts on the health of the community through the increased morbidity and mortality of the affected children, which leads to higher health care costs and compromised future productivity. The role of early enrollment into prenatal care in the improvement of perinatal outcomes has been established by many investigators. A health education strategy using a communication in the form of a videotaped program was designed in order to increase community awareness about this serious health problem and about the importance of early prenatal care. The purpose of this investigation was to evaluate that strategy by: determining the validity of the communication; analyzing its impact on related behavioral intentions of Community Board members; and assessing the association between behavioral intentions and reported behaviors in those Community Board members. A panel of experts in the fields of prenatal care/preterm birth or health education/communication was used to evaluate the face validity of the communication, using the Communication Rating Scale, an instrument developed by James Malfetti, Ed.D. The Fishbein Linear Regression Model was utilized in ascertaining attitudes and social normative factors predictive of behavioral intentions. A nonequivalent control group design was used to measure the impact of the communication on the behavioral intentions of 10 Community Boards in the Bronx, New York. The findings included high ratings by the expert panel; a positive significant difference behavioral intentions of Community Board members before and after viewing the communication; and significant correlation between behavioral intentions and reported behaviors. Since attitudes were found to be the best predictor of behavioral intention, this investigation concluded that a short potent communication can have a significant impact on attitudes of Community Board members. This evaluation of a community education program suggests that health educators can utilize this strategy in urban areas with poor health outcomes in order to impact on behavioral intentions of community leaders.

Women with schizophrenia and bipolar disorder are at a higher risk of obstetric and neonatal complications. The aim of this study was to better understand the factors that may influence these adverse outcomes. We examined obstetric and neonatal outcomes of pregnant women with schizophrenia and bipolar disorder and factors possibly influencing these outcomes. A retrospective review of the medical history of 112 women with a DSM-IV diagnosis of schizophrenia or bipolar disorder was undertaken. Data for controls were extracted from the hospital's electronic birth record data. Women with schizophrenia and bipolar disorder presented later for their first antenatal visit and had higher rates of smoking and illicit drug use than the control group. They also had higher rates of pre-eclampsia and gestational diabetes. Their infants were less likely to have Apgar scores 8-10 at both 1 and 5minutes and were more likely to be admitted to special care/neonatal intensive care nursery than the infants of controls. The rate of pre-term birth was significantly increased in the women with schizophrenia and bipolar disorder. Pre-term birth and admission to special care/neonatal intensive care were predicted by smoking and illicit drug use. These data point to potentially modifiable factors as significant contributors to the high rate of adverse obstetric and neonatal outcomes in women with mental illness. Comprehensive management of women with mental illness prior to, during pregnancy and in the postnatal period may have long-term benefits for their offspring.

Infants born before term (<37 weeks) have an increased risk of neonatal mortality as well as other health problems. The increasing rate of preterm birth in recent decades, despite improvements in health care, creates an impetus to better understand and prevent this disorder. Preterm birth likely depends on a number of interacting factors, including genetic, epigenetic, and environmental risk factors. Genetic studies may identify markers, which more accurately predict preterm birth than currently known risk factors, or novel proteins and/or pathways involved in the disorder. This review summarizes epidemiological and genetic studies to date, emphasizing the complexity of genetic influences on birth timing. While several candidate genes have been reportedly associated with the disorder, inconsistency across studies has been problematic. More systematic and unbiased genetic approaches are needed for future studies to examine the genetic etiology of human birth timing thoroughly.

Two biochemical tests, one for oncofetal fibronectin (fFN) and the other for estriol found in maternal saliva (SalEst) have been developed to improve the ability to predict preterm labor and birth. Fetal fibronectin is a protein secreted by the trophoblast and not normally present in vaginal and cervical secretions late in pregnancy. The presence of fFN between 22 and 37 weeks gestation may be a marker for preterm labor. Salivary estriol is a form of estrogen produced in the placenta from fetal precursors. Normally, estriol rises during pregnancy--the rise being accelerated 3 to 5 weeks prior to both term and preterm births. Both tests have high negative predictive values. This may serve to prevent unnecessary treatment of women with uterine contractions who are not truly in preterm labor. The fFN specimen is collected during vaginal examination. Sexual intercourse or vaginal examination within the prior 24 hours, vaginal bleeding, and uterine contractions may lead to a false positive test. Salivary estriol may be collected by the woman in her own home; however, specific instructions about eating, drinking, smoking, and the timing of saliva collection must be followed. Further study of both tests is required to determine their potential for reducing rates of preterm birth.

A multicenter, randomized placebo-controlled trial among women with singleton pregnancies and a history of spontaneous preterm birth found that weekly injections of 17 alpha-hydroxyprogesterone caproate (17P), initiated between 16 and 20 weeks of gestation, reduced preterm birth by 33%. The current study estimated both preterm birth recurrence and the potential reduction in the national preterm birth rate. Using 2002 national birth certificate data, augmented by vital statistics from 2 states, we estimated the number of singleton births delivered to women eligible for 17P through both a history of spontaneous preterm birth and prenatal care onset within the first 4 months of pregnancy. The number and rate of recurrent spontaneous preterm births were estimated. To predict effect, the reported 33% reduction in spontaneous preterm birth attributed to 17P therapy was applied to these estimates. In 2002, approximately 30,000 recurrent preterm births occurred to women eligible for 17P, having had a recurrent preterm birth rate of 22.5%. If 17P therapy were delivered to these women, nearly 10,000 spontaneous preterm births would have been prevented, thereby reducing the overall United States preterm birth rate by approximately 2%, from 12.1% to 11.8% (P < .001), with higher reductions in targeted groups of eligible pregnant women. Use of 17P could reduce preterm birth among eligible women, but would likely have a modest effect on the national preterm birth rate. Additional research is urgently needed to identify other populations who might benefit from 17P, evaluate new methods for early detection of women at risk, and develop additional prevention strategies. III.

Objectives: To assess the achievements and effectiveness of efforts to reduce preterm deliveries through the collaborative efforts of funding agencies, scientists, obstetricians, pediatricians, and health care providers in Canada. Methods: Chronological review of studies carried out in Canada within the past two decades using several methodological approaches, including randomized clinical trials, surveys of women and physicians, and prospective cohort studies. Results: Tertiary prevention by treatment of spontaneous preterm labor with beta-agonists was effective in delaying delivery by 48 hr compared with placebo. Ongoing studies tested the comparative efficacy of oxytocin antagonists to beta-adrenergic agents. Recently, nitric oxyde donors have been tested. Secondary prevention using various approaches showed that high-risk factors could not be modified by these interventions. Before applying primary prevention approaches, surveys disclosed the lack of knowledge among both physicians and pregnant women. Conclusion: A recent Canadian consensus meeting emphasized the potential for success by using multidisciplinary, community-based health promotion approaches to prevent preterm labor; enhancing basic research in predictive markers such as cervical change, infection/inflammation, and psychosocial stress; and increasing political involvement of health decision makers.