[Epidemiological characterization of COVID-2019 in Mexican pregnant women: a cohort study].

Background: COVID-19 in pregnancy can increase the risk of complications due to the cardiorespiratory and immunological changes typical of pregnancy. Objective: To report the epidemiological characterization of COVID-19 in Mexican pregnant women. Material and methods: Cohort study on pregnant women with a positive COVID-19 test, which were followed until delivery and one month later. Results: 758 pregnant women were included in the analysis. Mothers' mean age was 28.8 ± 6.1 years; the majority were workers 497 (65.6%) and with an urban origin (482, 63.6%); the most common blood group was O with 458 (63.0%); 478 (63.0%) were nulliparous women and more than 25% had some comorbidities; the average gestation weeks at infection were 34.4 ± 5.1 weeks; only 170 pregnant women (22.4%) received vaccination; the most frequent vaccine was BioNTech Pfizer (96, 60%); there were no serious adverse events attributed to vaccination. The mean gestational age at delivery was 35.4 ± 5.2 weeks; 85% of pregnancies were cesarean section; the most frequent complication was prematurity (406, 53.5%), followed by preeclampsia (199, 26.2%); there were 5 cases of maternal death and 39 cases of perinatal death. Conclusions: COVID-19 in pregnancy increases the risk of preterm birth, preeclampsia, and maternal death. Vaccination against COVID-19 in this series showed no risk for pregnant women and their newborns.