Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood Malignancy: A Population-Based Cohort Study in Ontario
Open Access
- 7 September 2010
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLoS Medicine
- Vol. 7 (9), e1000337
- https://doi.org/10.1371/journal.pmed.1000337
Abstract
The association between fetal exposure to major radiodiagnostic testing in pregnancy—computed tomography (CT) and radionuclide imaging—and the risk of childhood cancer is not established. We completed a population-based study of 1.8 million maternal-child pairs in the province of Ontario, from 1991 to 2008. We used Ontario's universal health care–linked administrative databases to identify all term obstetrical deliveries and newborn records, inpatient and outpatient major radiodiagnostic services, as well as all children with a malignancy after birth. There were 5,590 mothers exposed to major radiodiagnostic testing in pregnancy (3.0 per 1,000) and 1,829,927 mothers not exposed. The rate of radiodiagnostic testing increased from 1.1 to 6.3 per 1,000 pregnancies over the study period; about 73% of tests were CT scans. After a median duration of follow-up of 8.9 years, four childhood cancers arose in the exposed group (1.13 per 10,000 person-years) and 2,539 cancers in the unexposed group (1.56 per 10,000 person-years), a crude hazard ratio of 0.69 (95% confidence interval 0.26–1.82). After adjusting for maternal age, income quintile, urban status, and maternal cancer, as well as infant sex, chromosomal or congenital anomalies, and major radiodiagnostic test exposure after birth, the risk was essentially unchanged (hazard ratio 0.68, 95% confidence interval 0.25–1.80). Although major radiodiagnostic testing is now performed in about 1 in 160 pregnancies in Ontario, the absolute annual risk of childhood malignancy following exposure in utero remains about 1 in 10,000. Since the upper confidence limit of the relative risk of malignancy may be as high as 1.8 times that of an unexposed pregnancy, we cannot exclude the possibility that fetal exposure to CT or radionuclide imaging is carcinogenic. Please see later in the article for the Editors' SummaryKeywords
This publication has 40 references indexed in Scilit:
- Proliferation of prenatal ultrasonographyCMAJ : Canadian Medical Association Journal, 2010
- Exposure to Low-Dose Ionizing Radiation from Medical Imaging ProceduresNew England Journal of Medicine, 2009
- Using Discharge Abstracts to Evaluate a Regional Perinatal Network: Assessment of the Linkage Procedure of Anonymous DataInternational Journal of Telemedicine and Applications, 2008
- Children’s exposure to diagnostic medical radiation and cancer risk: epidemiologic and dosimetric considerationsPediatric Radiology, 2008
- Radiation Dose to the Fetus for Pregnant Patients Undergoing Multidetector CT Imaging: Monte Carlo Simulations Estimating Fetal Dose for a Range of Gestational Age and Patient SizeRadiology, 2008
- Patient dose in neonatal unitsRadiation Protection Dosimetry, 2008
- Trends in childhood cancer incidence in the U.S. (1992–2004)Cancer, 2007
- Childhood cancer in Ireland: a population-based studyArchives of Disease in Childhood, 2007
- Increasing utilization of computed tomography in the adult emergency department, 2000–2005Emergency Radiology, 2006
- Evidence for suboptimal use of periconceptional folic acid supplements globallyBJOG: An International Journal of Obstetrics and Gynaecology, 2004