Why were pregnant women excluded from the vaccine?

There’s a lot of confusion about the Covid vaccine and whether it’s safe for pregnant and breastfeeding women and their babies. Mums-to-be have written to me, asking why they were not given it from the start of the rollout if it is OK.

Medical trainees Helen Hare and Kate Womersley put together a convincing theory that it was down to a medical system that routinely discriminates against women.

Strong words? Well, they advance persuasive arguments.

When the Pfizer vaccine was first licenced the Medicines and Healthcare products Regulatory Agency (MHRA) recommended pregnant and breastfeeding women shouldn’t be given it. The NHS interpreted this as a ban even though it was at odds with the EU, US, and Canada, where women have been encouraged to make decisions based on their circumstances.

A month later, the MHRA revised its guidance so pregnant and breastfeeding women could receive the vaccine. The change came after pressure from campaigners, doctors, and affected women, including a piece by Hare and Womersley for BMJ Opinion. The MHRA’S U-turn is welcome news, but why were pregnant and breastfeeding women excluded in the first place?

As is traditional in clinical trials, Pfizer, Astrazeneca, and Moderna vaccine trials didn’t encompass pregnant and breastfeeding women so we have no safety data on them. But, Hare and Womersley point out, absent data is rarely a valid justification for blanket exclusions. Plus, there’s no plausible mechanism for how a Pfizer-type vaccine could harm a breastfed baby. The risk is theoretical and if weighed against the benefits of the Covid-19 vaccination, the jab would be given and breastfeeding continued.

In the view of Hare and Womersley, the MHRA’S approach wasn’t cautious as claimed, it was “reckless” to insist on exposing the women, their families, and, in the case of healthcare workers, their patients, to the lethal virus.

It’s not difficult to see how conflicted a woman would be to have to decide whether to stop breastfeeding or forgo vaccination. And of course stopping feeding abruptly risks breast engorgement and mastitis. Plus, it’s a sudden physical and emotional transition for a baby.

The MHRA now recommends breastfeeding women should have a “risk-benefit discussion with a healthcare provider” before receiving a Covid-19 vaccine. But this is really skating over the problem of having no data to support that strategy. Research on the vaccines’ safety in pregnant and breastfeeding women should be a top priority to fill the gap.

Hare and Womersley are right – ever since clinical trials began women have been overlooked. All early research on smoking and heart disease was done on men. For years we had no data on women. Surely not in this day and age.

‘‘ Since clinical trials began, females have been overlooked