Pregnant People Are Not in Covid-19 Vaccine Trials — and That’s a Problem

Excluding pregnant people from vaccine trials has been the default for decades, but experts say this should be rethought — especially now

Anna Nowogrodzki
Published in
6 min readDec 10, 2020


Photo: NurPhoto/Getty Images

In September, Molly Cohen, a city policy director in San Francisco, was reading a CNN article about Covid-19 vaccines and discovered a link at the bottom to volunteer for a clinical trial. She clicked right away. “I’m totally pro-vaccine,” she says. “Go science!” But when she told the portal she was pregnant, she was disqualified.

Pregnant and breastfeeding people have not been included in any of the Covid-19 vaccine clinical trials for the U.S. market, and it’s not clear what this will mean for that population when vaccines are rolled out. For example, will their exclusion delay rollout for them, or will it affect pregnant people’s trust that the vaccine is safe for them? How comprehensively will their reactions to the vaccines be recorded?

The benefits of vaccinating pregnant people are high because Covid-19 can pose risks for both pregnant people and their fetuses, although scientists don’t know (again because of lack of research) whether a Covid-19 vaccine given to a pregnant person would confer antibodies to a fetus. Medical and bioethics experts have written at least six articles since April in prominent medical journals like The Lancet and British Medical Journal urging that clinical trials for these vaccines include pregnant people. “Are they being included enough? Not at all,” says Atul Malhotra, a neonatologist at Monash Children’s Hospital in Melbourne, Australia.

Excluding pregnant people from clinical trials is not new. It’s the default, largely out of concern for fetuses, ever since the anti-morning-sickness drug thalidomide — which went straight from lab animal testing to commercial over-the-counter approval with no testing in any humans or pregnant animals — caused severe birth defects in fetuses in the 1950s and 1960s…