SARS-CoV-2 infection is associated with an increased risk of preterm birth, but only for women infected in their last trimester, according to research published in the open-access journal PLOS ONE. The study of more than 5,000 pregnant women is one of the first to look at pregnancy outcomes for COVID-19 patients by trimester.
There are limited data on pregnancy and COVID-19 infection. Studies to date have been small, generally limited to hospitalized patients, and often have not reported outcomes based on infection at different stages of pregnancy. Noga Fallach and colleagues at the Kahn-Sagol-Maccabi Research and Innovation Center used anonymized data captured by Maccabi Healthcare Services in Israel to match 2,753 women infected during pregnancy with 2,753 women without COVID-19 infection. reported. Their study took place from February 21, 2020 to July 2, 2021. Of the infected women, 17.4% contracted COVID-19 during the first trimester, 34.2% during the second and 48.4% during the first trimester. during the third trimester.
COVID-19 infection during the first and second trimesters was not associated with an increased risk of preterm delivery. However, women infected in their third trimester were 2.76 times more likely to have a preterm birth (2.76, 95% CI 1.63–4.67) – while women infected after 34 weeks of gestation were more than seven times more likely to have a preterm delivery (7,10, 95). % CI 2.44–20.61). There was a lower rate of waters breaking before onset of labor in infected women (39.1%) compared to uninfected women (58.3%), and the proportions of caesarean sections and baby loss were similar in both groups.
Because of the increased risk of preterm delivery in infected women late in pregnancy, researchers suggest that during their third trimester, and particularly after 34 weeks of gestation, women should be advised to move away and wear masks to reduce the risk of infection.
The results are encouraging and reassuring that COVID-19 infection during pregnancy is not associated with any type of pregnancy loss. However, it should be remembered that the research group tested pre-Delta COVID variants, and is not referring to the dominant variant today, which is Omicron. We continue to conduct research to provide real-world data and insights to the public and policy makers.”
Dr. Tal Patalon, Director of Kahn-Sagol-Maccabi (KSM), the research and innovation center of Maccabi Healthcare Services in Israel
Fallach, N. et al. (2022) Pregnancy outcomes after SARS-CoV-2 infection by trimester: a large population-based cohort study. PLOS ONE. doi.org/10.1371/journal.pone.0270893.