Evaluating birth outcomes following oral rilpivirine use in pregnancy in the United States: Findings from the antiretroviral pregnancy registry

Introduction The Antiretroviral Pregnancy Registry (APR) is designed to detect major teratogenic effects of antiretroviral medications; other pregnancy outcomes are also recorded when reported. We compared available pregnancy and birth outcomes of women exposed to oral rilpivirine‐containing regimens (oral‐RPV cohort) versus non‐rilpivirine regimens (non‐RPV cohort) over the period 2011 to 2023. Methods Maternal age‐adjusted prevalence ratio (aPR) of pregnancy and birth outcomes was compared for prospectively reported pregnancies; aPR of birth defects was compared between first‐trimester exposures and combined second/third‐trimester exposures. Results In total, 6937 pregnancies were recorded, including 4617 (oral‐RPV cohort, 781 [16.9%]; non‐RPV cohort, 3836 [83.1%]) from the United States. Among live births, the prevalence of birth defects was lower in the oral‐RPV cohort (1.6% versus 3.8%; aPR: 0.4 [95% confidence interval (CI): 0.2–0.8]). The prevalence of birth defects in the first‐trimester oral‐RPV exposure versus second/third‐trimester exposure did not differ (aPR: 3.4 [95% CI: 0.4–26.3]). The aPR of induced abortions (1.1 [0.6–1.9]), stillbirths (0.6 [0.2–1.6]) and premature birth (0.8 [0.7–1.1]) were similar between cohorts. Prevalences for spontaneous abortion were 5.8% (oral‐RPV cohort) versus 3.2% (non‐RPV cohort) below the expected background rate (15%–20%). Low birth weights were less reported in oral‐RPV, while very low birth weights were similar between cohorts. Conclusions Review of available data from the APR does not indicate an association between adverse pregnancy or birth outcomes and oral‐RPV exposure, overall or by timing of exposure. Since APR targets primarily teratogenic effects, findings for non‐teratogenic effects should be interpreted with caution.