The association between early pregnancy infection with SARS-CoV-2 and fetal birth defects: a prospective study

This multicenter prospective cohort study investigated the association between maternal SARS-CoV-2 infection in early pregnancy and birth defects. Although placental damage and fetal distress are known risks associated with SARS-CoV-2 infection during pregnancy, evidence regarding the impact of first-trimester infection on congenital anomalies remains limited. In this study, we prospectively enrolled 1,127 first-trimester pregnant women from three hospitals in China (535 SARS-CoV-2-infected, 592 non-infected as controls). The clinical characteristics, symptoms and treatment of COVID-19, and corresponding infant outcomes were followed-up and analyzed. Among singleton pregnancies, the incidence of total birth defects was significantly higher in the infected group than in the control group (9.2% vs. 4.7%, p = 0.004). Among the various types of birth defects, such as urinary system defects, nervous system defects, chromosome abnormality, etc., cardiovascular system malformations were the most prominent(3.4% vs. 1.5%, p = 0.048). Multivariate analysis identified first-trimester SARS-CoV-2 infection(RR = 2.25, 95%CI 1.38–3.56; p = 0.001) and twin pregnancy(RR = 4.52, 95%CI 1.83–8.95; p = 0.002) as independent risk factors. These findings demonstrate that early pregnancy SARS-CoV-2 infection correlates with an increased risk of birth defects, underscoring the need for enhanced prenatal monitoring in exposed pregnancies. The results highlight the critical importance of viral exposure timing in congenital anomaly development and support further investigation into the underlying pathogenic mechanisms.