The pregnancy outcomes of women with SARS-CoV-2 infection in the first trimester ---a longitudinal cohort study.

Background: In recent years, severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection has been prevalent worldwide. Pregnant women belong to a special group, and it is very important for clinicians to pay attention to the impact of SARS-CoV-2 infection on pregnancy outcomes. However, there are limited studies on the impact of SARS-CoV-2 infection on pregnancy outcomes during the first trimester.

Objective: To investigate the effect of SARS-CoV-2 infection in the first trimester on pregnancy outcomes.

Methods: Clinical information of pregnant women whose last menstrual period was between October 1, 2022, and April 1, 2023, and who were registered in the Obstetrics and Gynecology department of Peking University International Hospital, was analyzed. Among them, 498 pregnant women with SARS-CoV-2 infection in the first trimester were included in the study group; while a total of 654 pregnant women with no SARS-CoV-2 infection in the first trimester were included in the control group. Mann Whitney U test, χ2 test, Fisher's exact probability method, and multivariate logistic regression were used to analyze the impact of SARS-CoV-2 infection on pregnancy outcomes during the first trimester.

Results: A total of 30 cases in the study group experienced pregnancy loss before 28 weeks of gestation, and 468 cases delivered. In the control group, 41 cases experienced pregnancy loss before 28 weeks of gestation, and 613 cases delivered. The rates of pregnancy loss in the two groups were 6.02% and 6.27%, respectively, with no statistically significant difference between the two groups (P > 0.05). There was no statistically significant difference (P > 0.05) in the baseline data (delivery age, pre-pregnancy body mass index, gestational age, and parity) between the two groups. The rates of neonatal malformation, premature birth, premature rupture of membranes, postpartum hemorrhage, cesarean section, small for gestational age infants, low birth weight infants, macrosomia, and neonatal asphyxia were compared, with no statistically significant difference between the two groups (P > 0.05). However, the incidence of gestational hypertension in the study group was significantly higher than that in the control group (P = 0.012).

Conclusions: In this single center study, we found that SARS-CoV-2 infection in the first trimester may increase the risk of gestational hypertension, while the incidences of other adverse pregnant outcomes such as premature birth, premature rupture of membranes, cesarean section, postpartum hemorrhage, small for gestational age infants, low birth weight infants, and neonatal asphyxia did not significantly increase compared with women without SARS-CoV-2 infection in the first trimester.