The COVID-19 pandemic has particularly affected pregnant women, since if they become infected with the SARS-CoV-2 coronavirus, they are at greater risk of developing serious illness than women of the same age who are not expecting a baby. For this reason, experts have recommended the vaccination of pregnant women, but many feared that the COVID vaccines would have adverse effects that would affect the fetus.
New research has now proven that COVID-19 mRNA vaccines are safe during pregnancy and found that pregnant women had lower rates of health problems after vaccination than vaccinated non-pregnant women of similar age.
This study, from the Canadian National Network for Vaccine Safety (CANVAS), has been published in The Lancet Infectious Diseases and is one of the first to investigate the side effects of the COVID-19 vaccine in a group of vaccinated pregnant women , at the same time as a group of unvaccinated pregnant women and another group of vaccinated non-pregnant women in order to compare the three cases.
The most common significant health events after the second dose in pregnant women were malaise, headache/migraine, and respiratory tract infection
“In the early stages of the COVID-19 vaccine rollout, there was low uptake of the vaccine among pregnant people due to concerns about data availability and vaccine safety. There is still lower than average acceptance among non-pregnant women of reproductive age,” says Dr. Manish Sadarangani of British Columbia Children’s Hospital Research Institute and first author of this study.
“Large observational studies like ours are crucial to properly understand the rates of adverse health events in pregnant women after different doses of the COVID-19 vaccine. This information should be used to inform pregnant women of the side effects they may experience in the week “after vaccination.”
Abortion: there were no significant differences between vaccinated and non-vaccinated
The paper authors analyzed data from participants in seven Canadian provinces and territories between December 2020 and November 2021. All vaccinated participants will report any health event within seven days after each dose of the COVID vaccine, while the control group made up of unvaccinated pregnant women was asked to record any health problems during the seven days before completing the survey. A total of 191,360 women aged 15 to 49 years with a known pregnancy completed the first dose survey and 94,937 completed the second dose survey.
A “significant health event” was considered to be a health problem that was new or worse than causing enough discomfort that the participant missed school or work, needed to see a doctor, or prevented her from carrying out her daily activities within seven days. past days. “Serious health event” was defined as any event resulting in an emergency visit/or hospitalization in the previous seven days.
The researchers found that 4.0% (226/5,597) of mRNA-vaccinated pregnant women reported a significant health event within seven days of the first dose of an mRNA vaccine, and 7.3% ( 227/3108) after the second dose. The most common significant health events after the second dose in pregnant women were malaise, headache/migraine, and respiratory tract infection.
By comparison, 3.2% (11/339) of unvaccinated pregnant participants reported similar events in the seven days prior to taking the survey. In the control group of vaccinated nonpregnant women, 6.3% reported a significant health event in the week after dose one and 11.3% after the second dose. Serious health problems were rare in all groups (less than 1%) and occurred at similar rates in vaccinated pregnant and vaccinated non-pregnant individuals after doses one and two, and unvaccinated controls.
Miscarriage/delivery of a stillborn baby was the most frequently reported adverse pregnancy outcome, with no significant difference between rates in vaccinated and unvaccinated women; 2.1% of unvaccinated pregnant women and 1.5% of vaccinated pregnant women experienced a miscarriage or stillbirth within seven days of the first dose of any mRNA vaccine.
“The lower rate of significant health events among vaccinated pregnant women, compared to vaccinated non-pregnant individuals, is unexpected and requires further investigation. Previous studies of other vaccines in pregnant women have mostly reported no significant differences in health events between pregnant and non-pregnant women, or found higher rates in pregnancy,” said Julie Bettinger, lead author of this paper. and also from the British Columbia Children’s Hospital Research Institute.
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