Adverse Pregnancy and Child Outcomes in Oral Retinoid-Exposed Pregnancies: A Nationwide Population-Based Study

Background: Oral retinoids are used to treat various dermatological conditions, and their use is increasing in women of childbearing age. However, there is limited knowledge on the incidence of adverse outcomes after retinoid exposure during pregnancy. We aimed to evaluate the risk of adverse outcomes associated with oral retinoid exposure during pregnancy. Methods: We conducted a retrospective cohort study using the NHIS mother-child linked healthcare database in South Korea. We included all women who gave live birth from April 1, 2009 to December 31, 2020 and their children. The exposure was defined as having >= 1 prescription of isotretinoin, alitretinoin, and acitretin from one month before pregnancy to the delivery. The outcomes of interest were adverse child outcomes including major congenital malformations, low birth weight, and neurodevelopmental disorders (autism spectrum disorder and intellectual disorder), and adverse pregnancy outcomes including gestational diabetes mellitus, preeclampsia, and postpartum hemorrhage. Propensity score-based matching weights were used to control for various potential confounders. For congenital malformation, low birth weight, and adverse pregnancy outcomes, we calculated relative risk (RR) with 95% confidence interval (CI) using a generalized linear model and for neurodevelopmental disorders, we estimated hazard ratio (HR) with 95% CI using the Cox proportional hazard model. Results: Of 3,894,184 pregnancies, we identified 720 pregnancies (0.02%) as the oral retinoid-exposed group. The incidence of major congenital malformation was 400.6 per 10,000 births for oral retinoid-exposed group and 357.9 per 10,000 births for unexposed group and the weighted RR was 1.10 (95% CI, 0.65-1.85) in oral retinoid-exposed group compared with unexposed group. The neurodevelopmental disorder showed a potential increased risk, with the weighted HR of 1.63 (95% CI, 0.60-4.41) for autism spectrum disorder and 1.71 (95% CI, 0.60-4.93) for the intellectual disorder, although it did not reach statistical significance. For low birth weight and adverse pregnancy outcomes, no association was observed with oral retinoid exposure during pregnancy. Conclusion: This study found no significantly increased risk of congenital malformations, autism spectrum disorders, and intellectual disability associated with oral retinoid exposure during pregnancy; however, given the limitations such as including only the live births and increased point estimate, potential risk cannot be fully excluded.