Disease Outbreaks ; Humans ; Singapore ; epidemiology ; Zika Virus ; Zika Virus Infection ; epidemiology ; transmission ; virology

Absenteeism ; Emergency Service, Hospital ; Hospitals, General ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; epidemiology ; Personnel, Hospital ; Sentinel Surveillance ; Singapore ; epidemiology

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.
Abortion, Spontaneous/epidemiology* ; Adult ; COVID-19/transmission* ; COVID-19 Nucleic Acid Testing ; COVID-19 Serological Testing ; Cohort Studies ; Disease Transmission, Infectious/statistics & numerical data* ; Female ; Fetal Blood/immunology* ; Humans ; Infectious Disease Transmission, Vertical/statistics & numerical data* ; Live Birth/epidemiology* ; Maternal Age ; Milk, Human/virology* ; Obesity, Maternal/epidemiology* ; Placenta/pathology* ; Pregnancy ; Pregnancy Complications, Infectious/physiopathology* ; Pregnancy Outcome/epidemiology* ; Pregnancy Trimester, First ; Pregnancy Trimester, Second ; Prospective Studies ; RNA, Viral/analysis* ; Risk Factors ; SARS-CoV-2 ; Severity of Illness Index ; Singapore/epidemiology* ; Umbilical Cord/pathology* ; Young Adult