two studies reassure on vaccination during pregnancy
The anti-Covid Messenger RNA vaccines pose a small risk to pregnant women according to two recent studies, one of which in particular shows there is no particular risk of miscarriage or premature birth.
The first, published last week in The Lancet Infectious Diseases, assesses the immediate risk of side effects in pregnant women following a messenger RNA vaccine. The second, published Thursday in the British Medical Journal (BMG), measures the long-term risks of childbirth.
The two studies provide reassuring conclusions regarding these vaccines, one developed by Pfizer/BioNTech and the other by Moderna, which are at the heart of Covid vaccination in many countries such as France.
“Vaccination against Covid-19 during pregnancy is not associated with an increased risk of preterm birth (or) miscarriage,” summarize the BMJ authors, also concluding that there is no risk of the newborn being abnormally small.
This work, conducted in Canada, retrospectively studied more than 85,000 births or miscarriages that occurred between May and December 2021.
In about half of the cases, the mother received one or two doses of the Covid vaccine – mostly messenger RNA – during pregnancy. In the end, the outcome of pregnancy does not differ in this group.
As for the immediate side effects of RNA vaccines, they are generally no more frequent during pregnancy, according to the Lancet Infectious Diseases study.
two studies reassure on vaccination during pregnancy
The authors compared data on more than 5,000 women who were vaccinated during their pregnancies with data about 300 pregnant and unvaccinated women.
They measured the proportion of “significant” health problems—which would require interrupting an individual’s professional activity or consulting a physician—in the week following vaccination, in the first group, or in the week before answering the questionnaire, in the second week.
There is no difference after the Pfizer/BioNTech vaccine, or the first dose of Moderna. On the other hand, after the second dose of it, the risk increases slightly.
However, even after a second dose of Moderna, there is no difference if only conditions that require medical advice are taken into account.
The authors concluded that “Messenger RNA vaccines against Covid 19 have good safety properties during pregnancy.”
