The research gap
From 1977 to 1993, FDA guidance excluded women “of childbearing potential” from early drug trials. That guidance was replaced in 1993, but pregnant and breastfeeding women are still routinely excluded, so most medicines given to postpartum women were never tested on them.
This Is Why, Part 2 of 7: Women were left out of the research
In 1977, the FDA issued guidance saying women “of childbearing potential” should be excluded from the earliest stages of drug testing. The concern was harm to a possible pregnancy. (National Academies)
In practice, the phrase was read very broadly: any woman who could possibly become pregnant, regardless of contraception, relationships, or plans to have children. (Applied Clinical Trials) The exclusion meant for early studies ended up shrinking women’s presence across clinical trials generally.
It took 16 years to change. In 1993, Congress passed the NIH Revitalization Act, and on July 22, 1993, the FDA replaced the 1977 language with new guidance on studying sex differences in drug response. (National Academies)
That was progress. But two things are still true:
- Many medicines in use today were approved before 1993, when sex differences weren’t required to be studied. (Nursing Clio)
- Pregnant and breastfeeding women are still routinely left out of drug trials. The FDA itself says pregnant women have historically been excluded from drug development trials (FDA). Its guidance encouraging their inclusion only appeared in draft form in 2018 (Jones Day).
So when a pregnant or postpartum woman is handed a prescription, it is usually a medication that was never tested on someone in her situation. Her doctor is working from the evidence that exists. The problem is how little of it was ever gathered.
This is why.