Abstract [from journal]
Background: The COVID-19 pandemic caused by the SARS-CoV-2 virus has challenged obstetric care providers. Universal testing on labor and delivery units has been implemented by many hospitals to ensure patient and staff safety. Asymptomatic carrier rates are expected to vary based on geographic differences in disease prevalence, although differences within the same city have not previously been reported. Additionally, clinical follow-up of women testing negative for SARS-CoV-2 during obstetric hospitalization have not been included in any prior reports.
Objectives: To describe the prevalence of positive SARS-CoV-2 tests among asymptomatic pregnant women at two Philadelphia obstetric hospitals, characterize the clinical course of those testing positive, and report symptom development among all women tested in the two weeks post-hospitalization.
Study design: This is an observational study of asymptomatic pregnant women who underwent SARS-CoV-2 testing at two academic health centers (HUP and PAH) in Philadelphia, PA between April 13, 2020 and April 26, 2020. All women tested were contacted via telephone for symptom follow-up at one and two weeks post-discharge. Asymptomatic positive test rates are reported for the overall population and by hospital. The hospital and two-week post-hospital course are described for women testing positive for SARS-CoV-2. Post-hospital symptom development among women testing negative for SARS-CoV-2 is also described.
Results: Three hundred and eighteen asymptomatic women underwent SARS-CoV-2 testing during this two-week period. Eight women tested positive. The overall asymptomatic test positive rate was 2.5%. The rate at HUP was 3.8% compared to 1.3% at PAH (p = 0.283). Three women (37.5%) who were initially asymptomatic developed mild symptoms in the two weeks after positive test. Repeat SARS-CoV-2 testing was performed in 14 of the 310 women (4.5%) who initially tested negative; two women (0.6%) were positive on repeat testing. 242 (78.1%) and 213 (68.7%) of the 310 women who were SARS-CoV-2 negative at time of initial hospitalization were reached for telephone follow-up at one and two weeks post-admission, respectively. Viral symptoms, including fevers, chills, shortness of breath, or cough, were self-reported in 4.5% and 4.2% of these women at one and two weeks post-discharge, respectively.
Conclusions: The asymptomatic positive SARS-CoV-2 test rate among an obstetric population in Philadelphia differed between two hospitals and was lower than described in other geographic regions. This supports the importance of institution-specific testing protocols. The development of symptomatic SARS-CoV-2 infection post-hospitalization among women with initial negative testing is uncommon.