Assisted reproductive technology and placenta-mediated adverse pregnancy outcomes.

OBJECTIVE

To estimate whether the use of specific types of assisted reproductive technology (ART) is associated with an increased risk of placenta-mediated pregnancy complications, which include preeclampsia, stillbirth, small for gestational age at birth, and placental abruption.

METHODS

A population-based retrospective cohort study was conducted on singleton pregnancies conceived by different types of ART based on the 2004-2007 Ontario Niday Perinatal Database. Patients with fetal anomalies and maternal health problems were excluded as important confounders. Three exposed groups were created by the subtype of ART, including in vitro fertilization with or without intracytoplasmic sperm injection, intrauterine insemination, and ovulation induction. The nonexposed groups were the singleton pregnancies conceived naturally. For each exposed woman, four women from the nonexposed group were randomly matched by maternal age and parity.

RESULTS

There were 2,118 exposed participants and 8,420 matched nonexposed participants in the study. The sample size provided 80% power for a relative risk of 2.0 of placenta-mediated adverse pregnancy outcomes with ART. After adjustment of potential confounders, including smoking, delivery hospital level, initiating time of prenatal care, average neighborhood income, fetal sex, and previous cesarean delivery, there was no association observed between different types of ART groups and the composite of placenta-mediated pregnancy complications. Intrauterine insemination was associated with a significantly increased risk of preeclampsia (12 [2.67%] odds ratio 2.2, 95% confidence interval 1.04-5.04) compared with the corresponding control group (23 [1.29%]).

CONCLUSION

Assisted reproductive technology is not associated with an increased risk of the composite outcome of placenta-mediated pregnancy complications among singleton pregnancies.

LEVEL OF EVIDENCE: II.