Pregnancy Outcomes in Women Infected With COVID-19: A Retrospective Cohort Study

Introduction: Studies of the impact of the novel coronavirus 2019 (COVID-19) on pregnancy outcomes have yielded conflicting results. Objective: This study examined pregnancy outcomes in COVID-19-infected and non-infected pregnant women. Materials and Methods: In this retrospective cohort study, we included all pregnant women with (n=42) and without COVID-19 infection (n=185) admitted to a training and treatment center in Babol City, Iran, from March to November 2020. We abstracted the records of all pregnancies in women with COVID-19 (exposed cohort) and women without COVID-19 (non-exposed cohort). Patient information was taken from their medical records. The chisquare test and Student t-test were used for data analysis. Modified Poisson regression and mixed linear model were used to assess the adjusted risk ratio (aRR) and adjusted mean difference (aMD) between COVID-19 infection and pregnancy outcomes. Results: A total of 227 pregnant women (42 in the exposure group, 185 in the non-exposed group) were included in the study. The mean age of mothers was 28.12±6.27 years, and also 48.5% of them had their first pregnancy. In comparison with non-infected women, women with COVID-19 faced the highest risk of cesarean section (aRR: 2.22, 95% CI, 1.35%-3.65%, P=0.002) and preterm birth (aRR: 1.22, 95% CI, 1.02%-1.48%, P=0.026). Also, pregnant women with COVID-19 had a significantly higher duration of hospital stay (aMD: 2.20, 95% CI, 1.32%-3.08%, P=0.001) compared to pregnant women without COVID-19. There was no significant difference between the two groups in terms of postpartum hemorrhage and premature rupture of membranes. Conclusion: This study suggests that COVID-19 infection is associated with an increased risk of cesarean section, preterm birth, and increased duration of hospital stay but not with other outcomes. However, the current evidence does not support its causal effects, given the methodological limitations and small sample size.