Study population and setting
This case series included 116 pregnant women (mean age 30.8 years, median gestational age 38 weeks) with laboratory-confirmed or clinically confirmed COVID-19 from 25 hospitals in China from January 20 to March 4, 2020. Patient data were extracted from electronic medical records, including pregnancy and neonatal outcomes when available. Follow-up for outcomes was concluded on March 24, 2020. Neonatal pharyngeal swab samples were tested for presence of SARS-CoV-2 RNA. Additionally, a limited number of amniotic fluid, cord blood, vaginal secretions and breast milk samples were tested for SARS-CoV-2. The primary endpoint was a composite of ICU admission, mechanical ventilation, or death; secondary endpoints were spontaneous abortion, preterm delivery, Caesarean delivery, and vertical transmission of SARS-CoV-2 to neonates.
Summary of Main Findings
Eight patients had severe COVID-19 pneumonia and were admitted to the ICU; of these, two required invasive mechanical ventilation. There was one spontaneous abortion at five weeks. By the end of follow-up, there were no maternal deaths and 76 (66%) patients had been discharged. 99 (85%) women delivered babies during hospitalization, and 85 (86%) of these deliveries were Caesarean. No fetal deaths occurred; one neonate died of asphyxia two hours after birth, whose mother had required invasive mechanical ventilation after admission. Two births (2%) occurred before 34 weeks and 21 (21%) occurred before 37 weeks of gestation; of these, 6 involved preterm premature rupture of the membranes (PPROM). Zero positive tests for SARS-CoV-2 were observed among 86 neonates tested with pharyngeal swabs (10 of whom also had paired cord blood/amniotic fluid samples), vaginal secretion samples from 6 women, and breast milk samples from 12 women.
Relative to other studies of COVID-19 in pregnant women, this is a larger sample with reasonably long follow-up.
The pregnant women included in this study were symptomatic, and likely represent more severe clinical disease than all pregnant women infected with SARS-CoV-2. A large proportion (44%) of women were diagnosed clinically, without laboratory confirmation. By the end of follow-up, 40 women remained in the hospital, and 16 women had not yet delivered; outcome proportions may change with longer follow-up. Very few samples of vaginal secretion and breast milk were tested.
This is one of the largest studies to date of maternal and neonatal outcomes of SARS-CoV-2 infection in pregnant women.