Pregnancy Protection in Women of Childbearing Age Prescribed RAS Inhibitors or Statins: Cohort Study

Renin-angiotensin system inhibitors (RASIs) are known teratogens, while statins are potentially teratogenic. The study examined prescribing patterns of RASIs and statins alongside use of concomitant contraception among all women of child-bearing age in Denmark.

Nationwide registers were used to identify all women aged 15-50 years on RASIs, statins or calcium-channel blockers (CCB) during 2000-2023. Concomitant contraception was categorized as oral pill, implant, intrauterine device (IUD), or non-use. The duration of protection was assumed to be 180 days for oral contraceptives, two years for implants, and four years for IUDs.

In total, 141,351 women (median age 44 years) on RASIs, 79,814 (median age 45 years) on statins, and 86,173 (median age 44 years) on CCBs were included. The contraceptive coverage was 32.8% for RASI users, 25.2% for statin users and 30.8% for CCB users. Among RASI users on contraceptives, 66.4 % used oral contraceptives, 32.9% had IUDs, and 0.7 % had implants. For statin users, 66.3 % used oral contraceptives, 32.7% had IUDs, and 1.0 % had implants. Of the women on RASIs or statins 7.2% were on both drugs. For women aged 27-35 years, contraceptive use was 48.0 % among RASIs users, 44.5% for statin users and 39.9% for CCB users.

From 2000-2023, 141,351 women of child-bearing age were prescribed RASIs and 79,814 prescribed statins, most without concomitant prescription contraceptives, suggesting a public health risk of teratogenic exposure. Future studies should investigate the extent and impact of exposure during pregnancy.