The coronavirus represents a significant risk for pregnant women.
Pregnant women a
re no more at risk of being infected with the coronavirus, but the disease .
can have a significant impact on the course of their pregnancy. They are also more prone to severe forms of Covid-19. A statistical study published in Jama Pediatrics estimated the relative risk of developing complications inpositive pregnant women SARS-CoV-2 compared to those who are not infected.
Increased risk of complications for women with Covid-19 and pregnant
For a contaminated pregnant woman,.
scientists have compared two non-contaminated pregnant women with a similar profile and at the same stage of pregnancy. In total, 2,130 participants (median age: 30 years), including 706 infected with the coronavirus, who were followed for eight months. Thus, pregnant women have a higher relative risk (RR) of:
- preeclampsia / eclampsia (RR: 1.76);
- get a serious infection (RR: 3.38);
- be admitted to intensive care (RR: 5.04);
- maternal death which refers to the death of a woman within 42 days giving birth offrom a cause caused or aggravated by pregnancy (RR: 22.3);
- give birth naturally prematurely (RR: 1.59) or induce medically (RR: 1.97).
A portion (44%) of infected women contracted asymptomatic forms. Symptoms of Covid-19 as cough or fever also increase the relative risk of complications for the mother (RR, 2.56) and for the newborn (RR 4.97). Among the group of participants with Covid-19, eleven died, four of them from preeclampsia, five from worsening respiratory distress after childbirth, and two from fever, cough and respiratory problems. Pregnant women positive for SARS-CoV-2 are therefore more vulnerable to complications of pregnancy.
Pregnant women positive for SARS-CoV-2 exhibit robust inflammation in the placenta with activation of immune cells and genes stimulated by interferons. © Alice Lu-Culligan et al. Med, Cell Press
The inflammation responsible?
According to a second study, conducted at Yale University in the United States, it is not the virus itself that damages the placenta and therefore threatens mother and baby, but the immune response that is triggered there. placenta level. Indeed, the cells of the placenta (trophoblasts) express the ACE2 receptor, especially during the first trimester. In women with Covid-19, the expression of ACE2 in the placenta remains constant throughout pregnancy. However, coronavirus RNA has only been observed in the placenta after pregnancy in very rare cases.
In contrast, scientists observed a robust inflammatory response at the maternal-fetal barrier. cells Tand cells naturalkiller (NK)are activated, as were genes stimulated byinterferons.This situation is a double-edged sword since it allows the body to thwart the infection of the virus, but also weakens the placenta, markers characteristic of preeclampsia.
No cause-and-effect relationship has been established between the estimates presented in Jama Pediatrics and the observations made by the Yale team; these are two independent studies.
But the second offers an interesting mechanism that could help in understanding.
the risks faced by women who contract Covid-19 during their pregnancy.
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