Neonatal outcomes in singleton pregnancies conceived by fresh or frozen embryo transfer compared to spontaneous conceptions: a systematic review and meta-analysis
Open Access
- 21 May 2020
- journal article
- review article
- Published by Springer Science and Business Media LLC in Archiv für Gynäkologie
- Vol. 302 (1), 31-45
- https://doi.org/10.1007/s00404-020-05593-4
Abstract
Purpose The use of assisted reproductive technology (ART) has increased in the last 2 decades and continuous surveillance is needed. This systematic review aims to assess the risk of adverse neonatal outcomes (preterm birth [PTB], low birth weight [LBW], small-for-gestationalage [SGA] and large for gestational-age [LGA]), in singleton pregnancies conceived by fresh or frozen embryo transfer (FET) compared to spontaneous conceptions. Methods Cohort studies were identified from MEDLINE, Embase, Cochrane Library (January 2019), and manual search. Meta-analyses were performed to estimate odds ratios (OR) using random effects models in RevMan 5.3 and I-squared (I-2) test > 50% was considered as high heterogeneity. Results After 3142 titles and abstracts were screened, 1180 full-text articles were assessed, and 14 were eligible. For fresh embryo transfer, the pooled ORs were PTB 1.64 (95% CI 1.46, 1.84); I-2 = 97%; LBW 1.67 (95% CI 1.52, 1.85); I-2 = 94%; SGA 1.46 [95% CI 1.11, 1.92]; I-2 = 99%, LGA 0.88 (95% CI 0.80, 0.87); I-2 = 80%). For frozen, the pooled ORs were PTB 1.39 (95% CI 1.34, 1.44); I-2 = 0%; LBW 1.38 (95% CI 0.91, 2.09); I-2 = 98%; SGA 0.83 (95% CI 0.57, 1.19); I-2 = 0%, LGA 1.57 (95% CI 1.48, 1.68); I-2 = 22%). Conclusions When compared with spontaneous pregnancies, fresh, but not frozen was associated with LBW and SGA. Both fresh and frozen were associated with PTB. Frozen was uniquely associated with LGA. Despite improvements in ART protocols in relation to pregnancy rates, attention is needed towards monitoring adverse neonatal outcomes in these pregnancies.Keywords
Funding Information
- Canadian Institutes of Health Research (Grant MFM-146444)
This publication has 48 references indexed in Scilit:
- Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study from the CoNARTaS groupHuman Reproduction, 2013
- Why do singletons conceived after assisted reproduction technology have adverse perinatal outcome? Systematic review and meta-analysisHuman Reproduction Update, 2012
- Smaller fetal size in singletons after infertility therapies: the influence of technology and the underlying infertilityFertility and Sterility, 2011
- Infant outcome of 957 singletons born after frozen embryo replacement: The Danish National Cohort Study 1995–2006Fertility and Sterility, 2010
- Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analysesEuropean Journal of Epidemiology, 2010
- Congenital malformations in infants born after in vitro fertilization in SwedenBirth Defects Research Part A: Clinical and Molecular Teratology, 2010
- Obstetric Outcomes and Congenital Abnormalities After In Vitro Maturation, In Vitro Fertilization, and Intracytoplasmic Sperm InjectionObstetrics & Gynecology, 2007
- Increased risk of preterm birth in singleton pregnancies resulting from in vitro fertilization–embryo transfer or gamete intrafallopian transfer: A meta-analysisFertility and Sterility, 2004
- Pregnancy course and outcome after intracytoplasmic sperm injection: a controlled, prospective cohort studyFertility and Sterility, 2004
- Quantifying heterogeneity in a meta-analysisStatistics in Medicine, 2002