RALEIGH, N.C. (WNCN) – When COVID-19 vaccines were first approved for emergency use, they did not include safety data for pregnant women. That meant expectant mothers were making somewhat of a blind decision when choosing whether to get a COVID-19 vaccine.

With about 32 percent of the population now having had at least one dose of a COVID-19 vaccine, researchers are now learning what the vaccines mean for pregnant mothers and babies.

“Pregnancy does impact the immune system so people always wonder will the vaccine be less effective during pregnancy. But, it seems at least in the lab, that the antibody response is good,” said Dr. Rachel Urrutia, an OBGYN with UNC Health.

A study published in the American Journal of Obstetrics and Gynecology dealt with vaccine reactions in 131 women. It found neither the Pfizer or Moderna COVID-19 vaccine posed a threat to pregnant, lactating or nonpregnant women.

While it’s good news, Urrutia said the study was small, leaving a lot of uncertainty. One hundred-thirty one women were studied but only 11 were birth by the end of the study. It means we don’t know what vaccines mean for mothers in the long-term.

“Of course, many people who got the vaccine are still pregnant so it will take us a while to have that data,” said Urrutia.

An added bonus, the study found immunity was passed from mothers to their babies through the placenta and breast milk.

Urrutia herself received a COVID-19 vaccine while breastfeeding. She said she was not overtly concerned the vaccine would harm her or her child.

“I thought about it for a second because you always should, but not for too long,” said Urrutia.

Increased risks factors to moms-to-be

Still, she advises pregnant women that the risk from the vaccine is likely lower than the risk of COVID-19. Pregnant women are more likely to be hospitalized from COVID-19 or experience severe symptoms.

It’s still unclear what about the virus causes increased severity in symptoms.

“We’ve seen that pattern with SARS, we’ve seen that pattern with the flu, so it wasn’t unexpected for us,” said Urrutia.

Side effects

Below are the side effects felt in by women who were pregnant or lactating

Injection site soreness73 (88%)20 (67%)
Injection site reaction/rash1 (1%)0 (0%)
Headache7 (8%)9 (30%)
Muscle aches2 (2%)4 (13%)
Fatigue12 (14%)4 (13%)
Fever/chills1 (1%)1 (3%)
Allergic reaction0 (0%)0 (0%)
Other3 (4%)0 (0%)

Below are the side effects felt in by women who were pregnant or lactating after the second dose of a vaccine.

Injection site soreness44 (57%) 17 (61%)
Injection site reaction/rash1 (1%) 0 (0%)
Headache25 (32%) 11 (39%)
Muscle aches37 (48%) 16 (57%)
Fatigue41 (53%) 14 (50%)
Fever/chills25 (32%) 12 (43%)
Allergic reaction1 (1%) 0 (0%)
Other7 (9%)7 (25%)