Objective Previous studies comparing the COVID-19 pandemic period to prepandemic periods reported either no change or a decrease in extremely preterm birth (PTB) rates during the pandemic. 1, 2 These studies evaluated a limited number of potential PTB confounders and a short pandemic period. We aimed to determine the change in PTB rate and neonatal outcomes during the pandemic in comparison to prepandemic periods by evaluating multiple obstetrical characteristics, during more than three pandemic months. Study design We compared maternal, obstetrical and neonatal outcomes of singleton pregnancies at the Sheba Medical Center, Israel, during three periods: from 20/03/2020 (date of implementation of governmental state of lockdown) to 27/06/2020 (group 1), a parallel period in 2019 (group 2), and to another group that included the parallel annual periods in 2011-2019 (group 3) (see Table). We also compared maternal and pregnancy characteristics during the pandemic and corresponding prepandemic period in 2019 between pregnancies complicated by PTB <34 0/7 versus ≥34 0/7 weeks (see Table). Multivariate regression analysis was performed in order to study independent factors associated with PTB. The institutional review board approved this study (7068-20-SMC, 03/30/2020). Results There were 2,594 deliveries during the pandemic period (group 1) and 2,742 and 28,686 deliveries in the prepandemic periods (groups 2 and 3, respectively). Maternal and obstetrical characteristics did not differ between groups 1 and 2. Predelivery hemoglobin levels were higher in the pandemic period. PTB <34 0/7 weeks rate was significantly lower in the pandemic period compared to group 2 (OR 0.45 95% CI 0.30-0.68, p<0.001), as was the rate of composite neonatal outcome (OR 0.76 95% CI 0.59-0.96, p=0.023). Age, body mass index, parity, diabetes rates and hematologic characteristics differed between groups 1 and 3 with significantly higher predelivery hemoglobin levels in group 1. PTB <34 0/7 weeks rate was lower in the pandemic period (OR 0.60 95% CI 0.41-0.85, p=0.004). On multivariate regression analysis, delivering during the pandemic period was independently associated with a decreased risk for delivery <34 0/7 weeks (adjusted OR 0.29, 95% CI 0.15-0.56, p=0.001). Conclusion We observed more than 50% reduction in the rate of PTB <34 0/7 weeks of gestation, possibly resulting in improved neonatal outcome.

Key message Laboratory characteristics of SARS-CoV-2 infection did not differ between pregnant and non-pregnant women. A trend of lower lymphocyte count was observed in the pregnant women group Purpose Laboratory abnormalities, which characterize SARS-CoV-2 infection have been identified, nevertheless, data concerning laboratory characteristics of pregnant women with SARS-CoV-2 are limited. The aim of this study is to evaluate the laboratory characteristics of pregnant compared to non-pregnant women with SARS-CoV-2 infection. Methods A retrospective cohort study of all pregnant women with SARS-CoV-2 who were examined at the obstetric emergency room in a tertiary medical center between March and April 2020. Patients were compared with non-pregnant women with SARS-CoV-2 matched by age, who were examined at the general emergency room during the study period. All patients were confirmed for SARS-CoV-2 on admission. Clinical characteristics and laboratory results were compared between the groups. Results Study group included 11 pregnant women with SARS-CoV-2, who were compared to 25 non-pregnant controls. Respiratory complaints were the most frequent reason for emergency room visit, and were reported in 54.5% and 80.0% of the pregnant and control groups, respectively (p = 0.12). White blood cells, hemoglobin, platelets, and liver enzymes counts were within the normal range in both groups. Lyphocytopenia was observed in 45.5% and 32% of the pregnant and control groups, respectively (p = 0.44). The relative lymphocyte count to WBC was significantly reduced in the pregnant group compared to the controls [13.6% (4.5-19.3) vs. 26.5% (15.7-29.9); p = 0.003]. C-reactive protein [20(5-41) vs. 14 (2-52) mg/dL; p = 0.81] levels were elevated in both groups but without significant difference between them. Conclusion Laboratory characteristics of SARS-CoV-2 infection did not differ between pregnant and non-pregnant women, although a trend of lower lymphocyte count was observed in the pregnant women group.

COVID-19 infection imposes a risk for pregnant individuals and may lead to adverse maternal and obstetric outcomes. This is a retrospective cohort study of all women giving birth between March and July 2021 at a single tertiary center. Obstetric and neonatal outcomes were compared between vaccinated and non-vaccinated pregnant women with singleton pregnancies. Women with prior COVID-19 infection, multiple gestations and stillbirth were excluded from the study. Of 4708 women who delivered during the study period, 3700 met the eligibility criteria, of whom 3240 were vaccinated during pregnancy. Compared with the non-vaccinated group, the vaccinated group was characterized by a lower rate of smoking (3.70% vs 6.67%, p = 0.0028), whereasother maternal characteristics were not significantly different. Multivariable analysis demonstrated that COVID-19 mRNA vaccination was not significantly associated with increased risk of preterm birth as well as other adverse obstetric outcomes including hypertensive diseases of pregnancy, cesarean delivery and small for gestational age. However, a significantly lower risk for meconium-stained amniotic fluid was observed among the vaccinated group (adjusted odds ratio 0.63; 95% confidence interval, 0.46–0.86, p = 0.0039). Moreover, the vaccine was not significantly associated with increased risk of neonatal adverse outcomes including respiratory complications and NICU hospitalization. In conclusion, BNT162b2 messenger RNA vaccination during pregnancy was not associated with an increased rate of adverse obstetric and neonatal outcomes. Therefore, in view of its safety on one hand, and the risk associated with COVID-19 disease in pregnancy on the other hand, BNT 162b2 COVID-19 vaccine should be recommended for pregnant women.