Background: The recent US Supreme Court decision on abortion has triggered new abortion laws implemented by several states ranging from a complete ban (including medical indications) to specific gestational age (GA) cutoffs ranging from 6 to 22 weeks. The cutoff timing may affect the ability to consider pregnnacy termination if exposure to teratogenic medications is discovered too late.
Objectives: To estimate prenatal exposure risk to known teratogenic medications relative to the timing of prenatal care initiation and state abortion time windows.
Methods: We employed a previously validated pregnancy algorithm to identify pregnancies with live or non-live outcomes in MarketScan commercial claims data between 2017-2019. Women had continuous health plan enrollment with comprehensive drug coverage within 90 days before estimated conception to 30 days after pregnancy end. We evaluated exposure to 138 known teratogenic medications (TexRx) based on pharmacy dispensing or clinic administration dates. To identify prenatal care, we considered any medical encounter that indicated pregnancy allowing a broad range of clinical specialties. We summarized the number of pregnancy episodes exposed to teratogenic medications in relation to the time to initiation of prenatal care considering three cutoffs commonly used in new state abortion laws: 6, 15, and 22 weeks GA.
Results: A total of 639,994 pregnancies were available for analysis, including 472,472 (73.8%) live deliveries, of which 5.8% had prenatal exposure to a TexRx. Among pregnancies with non-live outcomes, 3.1% were exposed. A prenatal visit was identified for 467,499 (98.9%) live deliveries and 105,672 (63.1%) non-live deliveries, and occurred at a median of 52 days GA. Using the cutoff for legal abortions of 6 weeks GA, we found 8,186 pregnancies exposed to TexRx (25.2% of all pregnancies exposed to TexRx and 1.3% of all pregnancies). Only 5.3% of these had prenatal care before TexRx exposure and 76.8% initiated prenatal care after week 6. About half (48.9%) of TexRx-exposed pregnancies occurred at ≤15 weeks GA (2.5% of all pregnancies). Of these, 36.1% initiated prenatal care before exposure and 18.8% after week 15. Finally, prenatal exposure to TexRx occurred at ≤22 weeks GA for 64.4% of exposed pregnancies. 49.7% initiated prenatal care before TexRx. For 14.5%, prenatal care started after week 22.
Conclusions: Most prenatal exposure to TexRx occurs before common legal abortion cutoff and often precedes prenatal care. Prenatal care frequently starts too late to discuss potential pregnancy outcomes after TexRx or schedule an abortion, requiring potentially affected pregnancies to be carried to term or end of viability.
