Researchers in Scotland reported on Thursday that pregnant women with Covid are not only at greater risk of developing serious illness, but are also more likely to lose their fetuses and babies in utero or shortly after birth, compared with other women who gave birth during the pandemic. .
The risk of losing a baby to stillbirth or the first month of life was highest among women who delivered their babies within four weeks of onset of Covid infection: 22.6 deaths for every 1,000 births, four times the number in Scotland of 5.6 deaths per 1000 births.
All those deaths occurred during pregnancies in unvaccinated women, the researchers found. “Remarkably, there were no infant deaths in women who had SARS-CoV-2 and were vaccinated,” said Dr. Sarah J. Stock, lead author of the article, a specialist in maternal-fetal medicine at the Usher Institute of the University of Edinburgh in Exeter.
The study also found a higher rate of preterm birth in women diagnosed with Covid, a rate that peaked if the baby was born within a month of the mother becoming ill. More than 16 percent of these women gave birth before 37 weeks of pregnancy, compared to 8 percent in other women.
In Scotland, as in the United States, the vaccination rates of pregnant women are low. Only a third of pregnant women are vaccinated against the coronavirus, despite the protection offered by immunization. Early research has found no evidence that the Pfizer-BioNTech or Moderna vaccines pose any serious risks during pregnancy.
Indeed, the Scottish study found that the vast majority of infections in pregnant women occurred in women who had been completely unvaccinated or only partially vaccinated. Only 11 percent of total infections were reported in fully vaccinated pregnant women.
Pregnant women who had not been vaccinated were also four times more likely to be hospitalized compared to vaccinated pregnant women.
dr. Stock and her colleagues analyzed data collected by the Covid-19 study in Pregnancy in Scotland, a national cohort of all women who were pregnant or became pregnant after March 1, 2020, through the end of October 2021. The team followed 144,546 pregnancies in 130,875 women. in this period.
A weakness of the study is that the authors did not adjust for confounding factors, such as maternal age or pre-existing medical conditions, that could lead to poor pregnancy outcomes regardless of coronavirus infection or Covid diagnosis (they also did not know whether women who had been hospitalized for Covid disease, or who happened to test positive on admission).
Vaccination rates are low among pregnant women across the board, but are especially low among younger women and those of lower socioeconomic background, the study said. Future analyzes will take into account these demographic factors and other confounding factors, the authors said.
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Still, the differences in hospitalization, preterm birth and infant mortality between vaccinated and unvaccinated women are so great that those adjustments are unlikely to change the conclusions, said Dr. Stock and her colleagues.
They urged pregnant women to get vaccinated, following the pleas of health officials in the United States.
“The most important thing we want to bring home is that vaccination at the earliest opportunity is the best way to protect mother and baby, and it can be done at any stage of pregnancy,” said Aziz Sheikh, a population health researcher. at the University of Edinburgh and another author of the article.
“We now have enough information to get the really strong message about promoting vaccination during pregnancy,” said Rachael Wood, a public health consultant at Public Health Scotland, and a member of the research team.