No evidence of any risk to pregnant people, unborn children from COVID-19 vaccines: Dr. Reimer

Dr. Joss Reimer wants the message to be heard loud and clear: mRNA vaccines such as those from Pfizer-BioNTech or Moderna could save your life, but they won't negatively impact your fertility or pregnancy.

Breastfeeding can pass on anti-COVID antibodies, says medical lead for Manitoba's vaccine task force

A recent national study found that pregnant people were four times more likely to need ICU treatment if they got infected with COVID-19 than people who were not pregnant, Dr. Joss Reimer says. (Shutterstock)

Dr. Joss Reimer wants the message to be heard loud and clear: mRNA vaccines such as Pfizer-BioNTech's and Moderna's could save your life, but they won't negatively impact your fertility or pregnancy.

"There is no evidence that exists to suggest that any vaccines, including those that protect you from COVID-19, pose a clear health risk to people who are pregnant, nor to the unborn children," the medical lead of Manitoba's COVID-19 vaccine implementation task force said during Wednesday's provincial COVID-19 briefing.

In fact, they may well safeguard a fetus or a newborn because of the way antibodies are transferred through the mother, Reimer said.

Reimer also works in a clinic and specializes in the areas of sexual and reproductive health, and she's heard the questions many times over.

"I want to be able to reassure you about the vaccine," she said, noting there should be no concerns about negative impacts to fertility, menstruation, pregnancy or breastfeeding.

Rather, a vaccination should be a health-care priority throughout a pregnancy, because pregnant people are at an increased risk for severe outcomes from COVID-19, she said. 

A recent national study of 6,000 COVID-affected pregnancies across Canada found that pregnant people were four times more likely to need ICU treatment if they got infected with COVID-19 than people who were not pregnant. That risk only increased during the pandemic's third wave, Reimer said.

"At this point, the early reports are suggesting that the risk of needing ICU admission for someone who is pregnant and is infected with COVID-19 may be as high as 11 times the risk for someone who is not pregnant and the same age," she said. 

WATCH | Dr. Joss Reimer says it's important for pregnant people to get the COVID-19 vaccine:

COVID-19 vaccines are safe during pregnancy: Reimer

3 months ago
Dr. Joss Reimer says it's important for pregnant and breastfeeding people to get the COVID-19 vaccine because they are at an increased risk of hospitalization if they test positive for the virus. 1:07

The National Advisory Committee on Immunization recommends that anyone who is pregnant should get both doses of an mRNA vaccine. The Society of Obstetricians and Gynecologists of Canada also recommends they be offered to anyone who is pregnant.

A study of 4,000 pregnant people in the United States showed that not only is the two-dose vaccine safe, 97.6 per cent of participants remained COVID free, Reimer said.

"Some people have asked whether the COVID vaccines can help the developing fetus as well. The answer to that is yes," she said.

"The anti-COVID antibodies that a person develops when their immune system responds to the vaccine can cross the placenta. That means that they do go to the developing baby and can protect that baby after they're born."

Similarly, COVID-fighting antibodies that are developed in the immune response are found in breast milk. And in some of the lab studies of breast milk, the antibodies of vaccinated people were able to effectively stop the coronavirus that causes COVID-19 from functioning.

"This means there is a potential that consuming the breast milk can help protect a child from serious illness related to COVID," Reimer said, adding antibodies are detectable in breast milk two weeks after vaccination.

Vaccines are also safe for those hoping to become pregnant and their partners, she said.

"A person's ability to become pregnant will in no way be affected by getting vaccinated, and we have studies that have looked at this. One study looked at egg production before and after the vaccine, and found there was no impact."

Effect on menstruation 'not a heavily studied area'

Reimer said there are reports circulating online about possible changes to menstrual cycles — spotting or bleeding happening earlier than their expected periods — after receiving a COVID-19 vaccine.

There have also been claims that some people are having heavier periods or later periods or more uncomfortable periods following vaccinations, she said.

"In reality, the impact of vaccines on menstruation is not a heavily studied area of medicine," Reimer said.

If someone experienced heavy bleeding after receiving a vaccine, that would likely be reported and tracked in the province's system but minor changes such as spotting wouldn't likely be reported. 

Even in the absence of vaccines, periods can change due to many different factors such as sleep cycles, stress, diet and exercise, age or other health conditions, Reimer said.

"Irregular periods are incredibly common. This is something that people come to my clinic for often," she said.

"So while we are hearing these reports from individuals, the most likely explanation is that people are having changes to their period that they would have had anyway."

It is theoretically possible the vaccine could temporarily cause some irregular bleeding because the endometrium — the inside lining of the uterus — does have immune cells in it, Reimer noted.

"So while there's no evidence that this occurs, it's theoretically possible that the endometrium could temporarily experience a reaction along with the rest of the immune system."


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