In a recent study, University of Florida researchers sought to determine the prevalence and timing of prenatal exposure to teratogenic medications and prenatal care initiation relative to legal abortion cutoffs.
Their cross-sectional study of 639,994 pregnancies, published in the Journal of the American Medical Association Network Open, found that by 6 weeks’ gestation, 1.3% were exposed to teratogenic medications. Of those, prenatal care was initiated in 3.8% before teratogen exposure and in 84.0% after 6 weeks.
“By 15 weeks, teratogenic exposures had occurred in 2.5% of pregnancies, with prenatal care initiated after 15 weeks in 30.1%,” the researchers pointed out, adding, “Prenatal care commonly occurred after teratogen exposure and abortion cutoffs, prohibiting medication risk-benefit assessments and discussion of options, including pregnancy termination if concerns about teratogenic effects arose.”
The study noted that recent abortion restrictions have made the timing of prenatal care initiation critical to allow for discussion of reproductive options among pregnancies exposed to teratogenic medications.
The descriptive, population-based cross-sectional study used health encounter data from a national sample of individuals with employer-sponsored health insurance. A validated algorithm identified pregnancies among persons identifying as female that ended with a live or nonlive outcome between January 2017 and December 2019. Data were analyzed from December 2022 to December 2023.
The focus was on prenatal exposure to any of 137 teratogenic medications, measured via pharmacy and medical claims. Measurement of prenatal care initiation was adapted from the Children’s Health Care Quality Measures.
Among 639,994 pregnancies, 472,472 (73.8%; 95% CI, 73.7%-73.9%) had a live delivery (mean [SD] age, 30.9 [5.4] years) and 167,522 (26.2%; 95% CI, 26.1%-26.3%) had a nonlive outcome (mean [SD] age, 31.6 [6.4] years). The study reported that, of pregnancies with live deliveries, 5.8% (95% CI, 5.7%-5.8%) were exposed to teratogenic medications compared with 3.1% (95% CI, 3.0%-3.2%) with nonlive outcomes.
With the median time to prenatal care at 56 days (IQR, 44-70 days), by 6 weeks’ gestation, 8,186 pregnancies had been exposed to teratogenic medications (25.2% [95% CI, 24.7%-25.7%] of pregnancies exposed at any time during gestation; 1.3% [95% CI, 1.3%-1.3%] of all pregnancies); in 6,877 (84.0%; 95% CI, 83.2%-84.8%), prenatal care was initiated after 6 weeks or not at all, the authors pointed out.
By 15 weeks, teratogenic exposures had occurred for 48.9% (95% CI, 48.4%-49.5%) of all teratogen-exposed pregnancies (2.5% [2.4-2.5] of all pregnancies), they added, with prenatal care initiation occurring after 15 weeks for 1,810 (16.8%; 95% CI, 16.1%-17.5%) live deliveries and 2,975 (58.3%; 95% CI, 56.9%-59.6%) nonlive outcomes.
Teratogenic medications most used within the first 15 gestational weeks among live deliveries included:
• Anti-infectives (e.g., fluconazole)
• Anticonvulsants (e.g., valproate)
• Antihypertensives (e.g., lisinopril)
• Immunomodulators (e.g., mycophenolate).
For nonlive deliveries, most antihypertensives were replaced by vitamin A derivatives, according to the researchers.
Background information in the article noted that on June 24, 2022, the U.S. Supreme Court ended the constitutional right to an abortion, giving individual states the authority to regulate abortion access. Since then, abortion laws in individual states have changed rapidly; within a year, 14 states had fully banned abortion, sometimes without exceptions. Other states, such as Georgia, instituted bans after certain gestational age cutoffs—some as early as 6 weeks’ gestation. “Understanding the potential effects of these bans in the context of teratogenic medication exposures and access to pregnancy termination is critical,” the authors emphasized.
A concern, the researchers wrote, is that teratogenic medications are frequently prescribed for persons of childbearing potential. “About 1 in 16 pregnancies is exposed to a potentially teratogenic medication, with highest exposure levels during the first trimester,” according to the report. “For a few medications, the U.S. Food and Drug Administration requires risk evaluation and mitigation strategies (REMS)—safety programs that are designed to reinforce safe use behaviors. For example, iPLEDGE, the REMS for isotretinoin, requires patients to receive education, use effective contraception, and undergo pregnancy testing before receiving isotretinoin. Despite these strategies, isotretinoin-exposed pregnancies do occur.”
The authors argue that for pregnancies in which efforts to prevent exposure to teratogenic medications have failed, “Early initiation of prenatal care is essential to allow discussion of the potential risks, pregnancy monitoring for teratogenic effects, and discussion of options including pregnancy termination.”
An example cited is that among 2,720 pregnancies documented among more than 4 million patients who registered in the iPLEDGE program since its inception, 46% resulted in elective termination, 4.6% resulted in a live delivery, and 33.8% were lost to follow-up.
Pointing out that recognition of pregnancy onset varies, with a mean time to detection between 5 and 7 weeks’ gestation, the researchers noted that can result in delayed prenatal care initiation and also a delay in teratogenic exposure mitigation.
The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.
