Congenital Malformations in Singleton Infants Conceived by Assisted Reproductive Technologies and Singleton Infants by Natural Conception in Tehran, Iran

Multiple pregnancies occur more frequently in assisted reproductive technology (ART) compared to normal conception (NC). It is known that the risk of congenital malformations in a multiple pregnancy are higher than single pregnancy. The aim of this study is to compare congenital malformations in singleton infants conceived by ART to singleton infants conceived naturally.

In this historical cohort study, we performed a historical cohort study of major congenital malformations (MCM) in 820 singleton births from January 2012 to December 2014. The data for this analysis were derived from Tehran’s ART linked data file. The risk of congenital malformations was compared in 164 ART infants and 656 NC infants. We performed multiple logistic regression analyses for the independent association of ART on each outcome.

We found 40 infants with MCM 29 (4.4%) NC infants and 14 (8.3%) ART infants. In comparison with NC infants, ART infants had a significant 2-fold increased risk of MCM (P=0.046). After adjusting individually for maternal age, infant gender, prior stillbirth, mother’s history of spontaneous abortion, and type of delivery, we did not find any difference in risk. In this study the majority (95.1%) of all infants were normal but 4.9% of infants had at least one MCM. We found a difference in risk of MCMs between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). We excluded the possible role of genotype and other unknown factors in causing more malformations in ART infants.

This study reported a higher risk of MCMs in ART singleton infants than in NC singleton infants. Congenital heart disease, developmental dysplasia of the hip (DDH), and urogenital malformations were the most reported major malformations in singleton ART infants according to organ and system classification.