Obstetric and perinatal outcomes of pregnancies with COVID 19: a systematic review and meta-analysis

Objective: This meta-analysis aimed at comparing obstetric and perinatal outcomes in laboratory-tested pregnant women for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection before delivering. Method: We performed a comprehensive systematic review of electronic databases for studies reporting pregnant women with and without SARS-CoV-2 infection, as determined by polymerase chain reaction (PCR) before delivery, during the pandemic period published up to June 25, 2021. Results are reported as mean difference (MD) or odds ratio (OR) and their 95% confidence interval (CI). Results: Seventeen observational studies with low to moderate risk of bias, reported on 2,769 pregnant women with a positive SARS-CoV-2 PCR test and 13,807 with a negative test. Pregnant women with a positive PCR test delivered at an earlier gestational age (MD −0.19; 95% CI −0.36 to −0.02 weeks), smoked less (OR 0.75; 95% CI 0.61–0.94) and were associated with higher odds for preeclampsia (OR 1.30; 95% CI 1.09–1.54), NICU admissions (OR 2.37; 95% CI 1.18–4.76), stillbirths (OR 2.70; 95% CI, 1.38–5.29), and perinatal mortality (OR 3.23; 95% CI 1.23–8.52). There were no significant differences between positive and negative tested women in terms of nulliparity, multiple pregnancies, gestational diabetes, route of delivery, labor induction, preterm birth, infant birth weight, 5 min Apgar scores < 7, small-for-gestational-age infants and fetal malformations. Eleven studies included neonatal PCR SARS-CoV-2 testing which was performed on 129 infants, of which 20 were positive. Conclusion: Positive SARS-CoV-2 tested pregnant women had higher odds for preeclampsia/hypertensive disorders of pregnancy, NICU admissions, stillbirths and perinatal mortality.