Surveillance of congenital malformations in infants conceived through assisted reproductive technology or other fertility treatments.

Background: As assisted reproductive technology (ART) becomes more common, it is important to understand the associated risks. The objective of this study was to determine if congenital malformations are associated with ART or other fertility treatments in New York.

Methods: In a retrospective cohort study of all live births in upstate New York from 1997 to 2005, exposure was defined using ART or other fertility treatments as noted on birth certificates. Outcomes were assessed from the New York State Congenital Malformations Registry. Specific malformations were examined to determine if there is elevated risk for exposed singleton infants compared with infants conceived naturally.

Results: The study included 7120 in the ART group, 11,890 in the other fertility treatments group and 1,118,162 in the comparison group. The relative risk for a congenital malformation was 1.43 (95% CI 1.19-1.72) for singleton infants conceived through ART compared with singleton infants conceived naturally. The specific defects associated with ART were patent ductus arteriosus, hypospadias, and obstructive defect in the renal pelvis and ureter, while spina bifida, other specific anomalies of the spinal cord, atresia or stenosis of the pulmonary valve, hypospadias, and obstructive defects of the renal pelvis and ureter were associated with other fertility treatment.

Conclusion: Assisted reproductive technology is associated with a slight excess risk of birth defects. The specific congenital malformations with elevated risks for singleton infants vary depending on the exposure. Further research is necessary to understand the mechanism related to the increase in risk.