What’s the current advice on the COVID-19 vaccine and pregnancy?

Families/Kids Vaccines

A: Overall, there is no evidence that risks of vaccination would outweigh the benefits for pregnant women, but specific guidance varies by country.

Why no clear guidance?

As with almost all drug/vaccine trials, the current Phase III COVID-19 clinical trials did not include pregnant women (though some participants became pregnant during the Pfizer and Moderna trial, with no complications or increased risk of miscarriage).

Animal studies combined with a long track record of vaccines in pregnant humans suggest no reason to expect harmful effects to the fetus or mother. What’s more, 10,000 pregnant women have already been vaccinated with the mRNA vaccine in the US and while follow-up will be on-going, there are no red flags for safety.

The mRNA vaccines do not contain any virus particles and are eliminated within hours or days from the body, leaving minimal opportunity for unexpected long-term effects or effects on the fetus.

The dangers of COVID-19 infection for pregnant women on the other hand, while not high in absolute terms, are well-documented. A CDC study found that pregnant women 35 to 44 years old with COVID-19 were nearly four times as likely to require invasive ventilation and twice as likely to die than were non-pregnant women of the same age. (https://www.cdc.gov/mmwr/volumes/69/wr/mm6944e3.htm)

Another positive aspect of vaccination is that immunity from vaccination can cross the placenta and may help protect the baby from COVID-19 infection in its most vulnerable time shortly after birth. Recent studies demonstrating transfer of antibodies from natural COVID-19 infection to babies support this. These antibodies can also be passed through breast milk to the baby, providing additional protection.

Given the lack of specific clinical trial data for pregnant individuals coupled with the urgency of the pandemic, agencies have struggled to give consistent guidance.

In the US, the Centers for Disease Control (CDC), American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine agreed that the new mRNA vaccines *should* be offered to pregnant and breastfeeding individuals eligible for the vaccine.

In the UK, the Joint Committee on Vaccination and Immunisation (JCVI) is not recommending routine vaccination for pregnant women given the lack of data, but pregnant women at high risk for COVID-19 complications or in front line health or social care jobs are advised to discuss vaccination with their physician.

The WHO recently softened its advice from opposing vaccination for most pregnant individuals to advising that those at high risk due to exposures or underlying conditions “may be vaccinated in consultation with their health care provider.”

The lack of specific trial data has been seized upon by some to spread misinformation about the vaccine and fertility and pregnancy. We recommend this thoughtful piece by Drs. Alice Lu-Culligan & Akiko Iwasaki dispelling these myths while acknowledging the concerns and uncertainty women face (https://www.nytimes.com/…/opi…/covid-vaccine-rumors.html).


There are important potential benefits to the vaccine including preventing severe COVID disease that threatens both the mother and fetus, and the ability to pass along antibody protection through the placenta.

Nonetheless, because of the lack of clinical trial data, the decision remains a judgment call for individuals and their physicians.

If pregnant, we encourage assessment of your level of community transmission, personal exposures and underlying risk to discuss with your physician. The attached infographic/decision guide may help inform your conversation.

As always, more data are on the way, and we will continue to keep you updated on any new info.

*Especially* if you are expecting, Stay safe and Stay sane!

Those Nerdy Girls

Further reading:
“Wondering about COVID-19 vaccines if you’re pregnant or breastfeeding?”

Guidance from the American College of Obstetricians and Gynecologists:

“Pregnant Women get Conflicting Advice on Covid-19 Vaccines.”

Recent JAMA article on COVID-19 infection and maternal antibodies:

Link to full Infographic/Decision Aid in multiple languages:

Link to original FB post