OBJECTIVE: To estimate the prevalence of major birth defects diagnosed by 6 years of age in all births and terminations of pregnancy for fetal anomaly conceived by assisted reproductive technology (when this included intracytoplasmic sperm injection and in vitro fertilization [IVF]) and the remainder of nonassisted reproductive technology–conceived children born in Western Australia from 1994 to 2002.
METHODS: This retrospective cohort study used data linkage between three population-based registers (Reproductive Technology Register, Western Australian Register of Developmental Anomalies, and Midwives' Notification of Birth System) to identify all assisted reproductive technology (n=2,911) and nonassisted reproductive technology (n=210,997) births with and without birth defects diagnosed by age 6 and all terminations of pregnancy for fetal anomaly.
RESULTS: A major birth defect was diagnosed in 8.7% of assisted reproductive technology and 5.4% of nonassisted reproductive technology singletons (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.30–1.79), as well as 7.1% of assisted reproductive technology twins and 5.9% of nonassisted reproductive technology twins of unlike sex (OR 1.08, 95% CI 0.77–1.51). The prevalence of birth defects in assisted reproductive technology singletons and twins decreased markedly over the study period. This change was evident across all three clinics contributing data over the whole study and was particularly marked for children conceived as a result of IVF.
CONCLUSION: There has been a decrease in the prevalence of birth defects over time in children born as a result of assisted reproductive technology in Western Australia; however, the prevalence of major birth defects in assisted reproductive technology singletons remains increased compared with nonassisted reproductive technology singletons.
LEVEL OF EVIDENCE: II
The prevalence of major birth defects in children born as a result of assisted reproductive technology in Western Australia has decreased over time.
From the Division of Population Sciences and the Department of Biostatistics and Bioinformatics, Telethon Institute for Child Health Research and the Centre for Child Health Research, University of Western Australia, Perth, and Concept Fertility Centre and the Western Australian Register of Developmental Anomalies, King Edward Memorial Hospital, Subiaco, Western Australia; and the National Perinatal Epidemiology Unit, University of Oxford, Oxford, United Kingdom.
The authors thank the Western Australian Data Linkage Branch and Health Data Custodians for linkage of and access to core health data sets, the WA Reproductive Technology Council for permission to use data from the RT Register, and Register and Fertility Centre staff for their assistance with data queries.
Supported by an Australian National Health and Medical Research Council (NHMRC) project grant (211930), NHMRC programme grant (572742), and NHMRC Research Fellowship 634341 (Carol Bower).
Corresponding author: Michele Hansen, Telethon Institute for Child Health Research, PO Box 855, West Perth, Western Australia 6872; e-mail: firstname.lastname@example.org.
Financial Disclosure The authors did not report any potential conflicts of interest.