Association between SARS-CoV-2 infections during pregnancy and preterm live birth

We examined associations between mild or asymptomatic prenatal SARS-CoV-2 infection and preterm live birth in a prospective cohort study. During August 2020-October 2021, pregnant persons were followed with systematic surveillance for RT-PCR or serologically confirmed SARS-CoV-2 infection until pregnancy end. The association between prenatal SARS-CoV-2 infection and preterm birth was assessed using Cox proportional-hazards regression. Among 954 pregnant persons with a live birth, 185 (19%) had prenatal SARS-CoV-2 infection and 123 (13%) had preterm birth. The adjusted hazard ratio for the association between SARS-CoV-2 infection and preterm birth was 1.28 (95% confidence interval 0.82-1.99, p = 0.28), although results did not reach statistical significance.

Automated summary

We conducted a prospective cohort study to investigate the association between mild or asymptomatic prenatal SARS-CoV-2 infection and preterm live birth. Pregnant individuals were monitored for SARS-CoV-2 infection using RT-PCR or serological confirmation from August 2020 to October 2021. Cox proportional-hazards regression was used to assess the association between prenatal SARS-CoV-2 infection and preterm birth. Among 954 individuals with a live birth, there were 185 (19%) with prenatal SARS-CoV-2 infection and 123 (13%) with preterm birth. The adjusted hazard ratio for the association between SARS-CoV-2 infection and preterm birth was 1.28 (95% confidence interval 0.82-1.99, p = 0.28), although the results were not statistically significant.