Covid mRNA Vaccines Safe For Pregnant People, New Study Reinforces

Topline

In a finding that provides more reassurance of the safety of Covid-19 messenger RNA vaccines for pregnant people, a Canadian study found pregnant women—who are at higher risk for more severe coronavirus infections—actually experienced fewer significant health problems after getting vaccinated than non-pregnant people of the same age.

Key Facts

The observational study, published in the journal Lancet Infectious Diseases, compared side effects for pregnant women after receiving Pfizer and Moderna mRNA vaccines to a control group of vaccinated non-pregnant women of the same age as well as a group of unvaccinated pregnant women.

Researchers found 7.3% of pregnant women experienced health issues requiring time off from work or medical attention like headaches and fatigue within a week of a second dose of the Pfizer and Moderna vaccines, compared to 11.3% of non-pregnant vaccinated women.

The most common health problems for pregnant women after getting the second dose included a general feeling of being unwell, headaches and migraines and respiratory tract infections.

Among all three groups, there was no significant difference in rates of more serious health problems that required professional medical attention, researchers found, though they noted one study limitation was the sample population, which was largely white.

Pregnant women have gotten vaccinated at lower rates than non-pregnant women because of concerns about safety, and such studies can help inform them about potential vaccine side effects as well as the overall safety of the shots, study author Manish Sadarangani, the head of the Vaccine Evaluation Center at British Columbia Children’s Hospital Research Institute, said in a statement.

Tangent

Vaccination rates among pregnant women in the United States have climbed over the past year, according to data from the Centers for Disease Control. Roughy 45% of pregnant women were fully vaccinated against Covid as of mid-July 2021, compared to some 71% of pregnant women at the end of July 2022.

Key Background

The study adds to a growing body of research suggesting Covid mRNA vaccines are safe for pregnant women and not linked to an increased risk of miscarriage, preterm labor, or other negative birth outcomes. The Lancet study is also one of the first to compare pregnant women to both non-vaccinated pregnant women and vaccinated non-pregnant women. Pregnancy puts women at a higher risk for severe Covid infections including hospitalization, ventilation and death because of physiological changes to women’s immune systems and heart and lung health, researchers noted. Women are also at a higher risk of adverse pregnancy health outcomes as a result of Covid infections, including hypertension, preeclampsia, impaired fetal growth and preterm birth. Still, vaccination uptake among pregnant women lagged in the early stages of the coronavirus vaccine rollout because of data availability, researchers noted, while misinformation about the safety of the shot for pregnant women may also have increased vaccine hesitancy.

Surprising Fact

Some research suggests pregnant women who are vaccinated against Covid during their pregnancies may even pass down their coronavirus antibodies to their children. One recent study found 57% of 6-month-old infants whose mothers were vaccinated during their pregnancy had antibodies against the coronavirus, compared to 8% of infants whose mothers had a coronavirus infection during pregnancy.

Further Reading

How Misinformation About COVID Vaccines and Pregnancy Took Root Early On and Why It Won’t Go Away (ProPublica)

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