Exposure of Drugs for Hypertension, Diabetes, and Autoimmune Disease During Pregnancy and Perinatal Outcomes: An Investigation of the Regulator in Japan

Assessment of perinatal effects of drug exposure during pregnancy after approval is an important issue for regulatory agencies. The study aimed to explore associations between perinatal outcomes and maternal exposure to drugs for chronic diseases, including hypertension, diabetes, and autoimmune disease. We reviewed 521 cases of adverse reactions due to drug exposure during pregnancy who were reported to the Pharmaceuticals and Medical Devices Agency, a regulatory authority in Japan. The primary outcomes were fetal and neonatal death and malformation of infants. Associations between perinatal outcomes and exposure to each drug category for hypertension, diabetes, and autoimmune disease were evaluated using logistic regression analysis. Of the 521 cases (maternal age: 15–47 years; mean 32.3 ± 5.5), fetal and neonatal deaths were reported in 159 cases (130 miscarriage; 12 stillbirth; 4, neonatal death; and 13 abortion due to medical reasons), and malformations of infants were observed in 124 cases. In contrast to the trend of association between diabetes with or without medication and fetal and neonatal death (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.17–1.36), exposure to oral antidiabetics tended to be associated with fetal and neonatal death (OR, 4.86; 95% CI, 0.81–29.2). Malformation tended to be correlated with exposure to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (OR, 2.98; 95% CI, 0.76–11.7). This association showed trends opposite to that of the association with hypertension itself (OR, 0.42; 95% CI, 0.18–1.02) or overall antihypertensives (OR, 0.42; 95% CI, 0.15–1.13). Occurrence of multiple malformations was associated with exposure to biologics (OR, 8.46; 95% CI, 1.40–51.1), whereas there was no significant association between multiple malformations and autoimmune disease with or without medication (OR 1.07; 95% CI, 0.37–3.06). These findings suggest that drugs of different categories may have undesirable effects when used during pregnancy. However, the regulatory database was not originally designed to evaluate the causal associations between drug exposure and adverse drug reactions. The limitations of spontaneous reporting systems should be carefully taken into account. Further studies are needed to elucidate the effects of individual drugs in each category on perinatal outcomes.