• Vol. 49 No. 11, 857–869
  • 01 November 2020

Pregnancy Outcomes in COVID-19: A Prospective Cohort Study in Singapore



Download PDF


Introduction: Pregnant women are reported to be at increased risk of severe coronavirus disease 2019 (COVID-19) due to underlying immunosuppression during pregnancy. However, the clinical course of COVID-19 in pregnancy and risk of vertical and horizontal transmission remain relatively unknown. We aim to describe and evaluate outcomes in pregnant women with COVID-19 in Singapore. Methods: Prospective observational study of 16 pregnant patients admitted for COVID-19 to 4 tertiary hospitals in Singapore. Outcomes included severe disease, pregnancy loss, and vertical and horizontal transmission. Results: Of the 16 patients, 37.5%, 43.8% and 18.7% were infected in the first, second and third trimesters, respectively. Two gravidas aged ≥35 years (12.5%) developed severe pneumonia; one patient (body mass index 32.9kg/m2 ) required transfer to intensive care. The median duration of acute infection was 19 days; one patient remained reverse transcription polymerase chain reaction (RT-PCR) positive >11 weeks from diagnosis. There were no maternal mortalities. Five pregnancies produced term live-births while 2 spontaneous miscarriages occurred at 11 and 23 weeks. RT-PCR of breast milk and maternal and neonatal samples taken at birth were negative; placenta and cord histology showed non-specific inflammation; and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunoglobulins were elevated in paired maternal and umbilical cord blood (n=5). Conclusion: The majority of COVID-19 infected pregnant women had mild disease and only 2 women with risk factors (obesity, older age) had severe infection; this represents a slightly higher incidence than observed in age-matched non-pregnant women. Among the women who delivered, there was no definitive evidence of mother-to-child transmission via breast milk or placenta.

Since the first cases of coronavirus disease 2019 (COVID-19) in pregnancy were described, significant concerns have been raised about the potentially increased susceptibility of pregnant women to severe disease, and the unquantified risk of mother-child transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the fetus and neonate. Despite our experience with other β coronavirus infections in pregnancy, including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), many questions remain regarding the clinical course of COVID-19 in pregnancy. A case series of 116 cases from Wuhan, China, reported a 6.9% incidence of severe pneumonia but no mortality among infected pregnant women, in contrast to the case fatality rate of 1–3% in the general population. Earlier case series from Italy, the US and Sweden also reported no maternal mortalities and critical care admission in <10% of infected gravidas, findings similar to systematic reviews involving >160 pregnancies that described favourable maternal and fetal outcomes, possibly related to pregnancy-specific physiological changes that mitigate COVID-19 severity.

This article is available only as a PDF. Please click on “Download PDF” to view the full article.