Methods
This was a retrospective cohort study conducted at a single university affiliated, tertiary medical center. The center treats a heterogeneous population with over 10,000 deliveries per year. The study cohort included pregnant women admitted to the obstetrical emergency unit for delivery during the mask-wearing period during the COVID-19 pandemic (April 19 to June 27, 2020), starting seven days after initiation of the mask-wearing regulations in our country, to account for the delay between erythropoietin secretion and the rise in hemoglobin levels. We compared these women’s characteristics and outcomes to two pre-pandemic time frames- the parallel period in 2019 (April 19 to June 27, 2019), and a longer period between March 21, 2011 and April 18, 2020.
We abstracted labor and delivery charts from the electronic medical record database of the labor and delivery ward of our center. The following data were extracted: patient characteristics (age, body mass index, smoking, COVID-19 infection status and hemoglobin, platelets, fibrinogen and white blood cells levels); delivery and postpartum characteristics (gestypothermic treatment.
Maternal body mass index (BMI) was calculated according to height and weight at admission. Post-partum hemorrhage was defined by The American College of Obstetricians and Gynecologists as cumulative blood loss of greater than or equal to 1,000 mL or blood loss accompanied by signs or symptoms of hypovolemia within 24 hours of the birth process. Composite bleeding was defined as the presence of post-partum hemorrhage of blood products transfusion. Composite neonatal outcome included the presence of any of the neonatal outcomes studied.
Institutional review board approval was obtained for this retrospective study on March 30,2020 (# 7068-20-SMC).