Are assisted reproductive technology pregnancies more likely to be exposed to teratogenic medication? A whole-population study

Background

Assisted reproductive technology (ART) pregnancies are at greater risk of birth defects than non-ART pregnancies. Teratogenic medication exposure is a potential cause of birth defects that has not been compared between ART and non-ART pregnancies.

Aims

To determine whether the prevalence of exposure to teratogenic medicines during pregnancy varies by conception method (ART and three non-ART groups: ovulation induction (OI), subfertile untreated, and fertile naturally conceiving).

Materials and Methods

We linked state and commonwealth datasets for all live and stillbirths (≥20 weeks) in Western Australia with a conception date ≥1 July 2012 and date of birth ≤31 December 2014. We calculated the prevalence of exposure to teratogenic medicines (Therapeutic Goods Association Category D/X) across conception groups for the: (i) first trimester, and (ii) second and third trimesters.

Results

We identified 2041 ART, 590 OI, 2063 subfertile and 52 987 fertile pregnancies (57 681). The overall prevalence of exposure to Category D/X medicines was 0.8% in the first trimester, and 0.7% in the second and third trimesters. Category X medicines exposure was <0.5% for all conception groups and trimesters. The first trimesters of ART and OI pregnancies were more often exposed to Category D medicines than subfertile and fertile pregnancies, (ART = 4.9%, OI = 2.0% vs subfertile = 1.3%, fertile = 0.6%) as were later trimesters (ART = 3.4%, OI = 1.4% vs subfertile = 0.9%, fertile = 0.6%).

Conclusions

The overall prevalence of exposure to teratogenic medicines is low; however, exposure was greatest in pregnancies arising from ART and may be a modest contributing factor to the higher rate of birth defects observed among ART babies.