5 Key Takeaways

• 1

  This retrospective cohort study analyzed 218,234 pregnancies with respiratory tract infections and 6,636 pregnancies with acne in US claims databases.

• 2

  For respiratory tract infections, first-trimester doxycycline exposure was associated with higher adjusted relative risks of pregnancy loss than amoxicillin or macrolides in both databases.

• 3

  For acne, doxycycline was associated with higher pregnancy loss risk than topical clindamycin in MarketScan, but not in Medicaid.

• 4

  Sensitivity analyses generally supported the respiratory tract infection findings, while stillbirth-specific results were inconclusive because of few events.

• 5

  The observational study could not establish causality and was limited by possible exposure misclassification, missed early losses, and residual confounding.