What drugs are safe during pregnancy? There's a shocking lack of data

"In 2021, amid the COVID‑19 pandemic, Kristin Wall became pregnant with her second child. Her physician told her that little was known about the COVID-19 vaccine's safety and effectiveness in pregnant people. Observational data - collected from those vaccinated before they knew that they were pregnant - suggested that the vaccine was safe, so she could have it. Still, she'd have to weigh up the risks and benefits herself."

"Wall is an epidemiologist at Emory University in Atlanta, Georgia, and is therefore unusually qualified to assess health risks. But her experience is a common one - and far from unique to COVID-19. When it comes to pregnancy, people must often make important medical decisions with limited or imperfect information, says Wall. Pregnancy changes the body, including how it metabolizes and distributes medications, so a drug with a predictable effect in a non-pregnant person might work very differently in someone who is pregnant."

"There is now solid evidence from the huge numbers of people vaccinated, and subsequent clinical trials, that the COVID-19 vaccines that use messenger RNA (mRNA) - as well as influenza vaccines and others that do not use live viruses - are generally safe and effective during pregnancy. Safety is also well established for certain other medications: some anti-allergy drugs, some antidepressants and some antibiotics are considered safe for use in pregnancy."

Many pregnant people must decide about medications with limited or imperfect information because pregnancy alters drug metabolism and distribution. Observational data initially suggested COVID‑19 vaccines were safe when given unknowingly during early pregnancy, requiring individual risk–benefit weighing. Large vaccination numbers and clinical trials now show mRNA COVID‑19 vaccines, inactivated influenza vaccines and other non-live vaccines are generally safe and effective in pregnancy. Certain other medications — some anti-allergy drugs, some antidepressants, some antibiotics and paracetamol — are considered safe. Some drugs, such as sodium valproate, carry clear fetal risk. Despite high medication use in pregnancy, safety data remain lacking for many drugs.

Read at Nature