Obstetrical outcomes and follow-up for patients with asymptomatic COVID-19 at delivery: a multicenter prospective cohort study

BACKGROUND: Universal testing for COVID-19 on admission to the labor and delivery unit identifies asymptomatic patients. Whether or not these patients are at increased risk for adverse outcomes and go on to develop clinically significant disease is uncertain. OBJECTIVE: This study aimed to assess the prevalence of asymptomatic COVID-19 presentation among pregnant patients admitted for delivery and to determine whether these patients become symptomatic or require hospital readmission after discharge. STUDY DESIGN: We performed a multicenter, prospective cohort study of pregnant patients who delivered between 20(0/7) and 41(6/7) weeks’ gestation and who were found to have COVID-19 based on universal screening on admission for delivery at 1 of 4 medical centers in New Jersey (exposed group). The unexposed group, comprising patients who tested negative for COVID-19, were identified at the primary study site. The primary outcomes were the rates of asymptomatic COVID-19 presentation, the development of symptoms among the asymptomatic positive patients, and hospital readmission rates in the 2 weeks following discharge. We compared the frequency of the distribution of risk factors and outcomes in relation to the COVID-19 status among patients with COVID-19 across all centers and among those without COVID-19 at the primary site. Associations between categorical risk factors and COVID-19 status were expressed as relative risks with 95% confidence intervals. RESULTS: Between April 10, 2020, and June 15, 2020, there were 218 patients with COVID-19 at the 4 sites and 413 patients without COVID-19 at the primary site. The majority (188 [83.2%]) of patients with COVID-19 were asymptomatic. Compared with the negative controls, these asymptomatic patients were not at increased risk for obstetrical complications that may increase the risk associated with COVID-19, including gestational diabetes (8.2% vs 11.4%; risk ratio, 0.72; 95% confidence interval, 0.24–2.01) and gestational hypertension (6.1% vs 7.0%; risk ratio, 0.88; 95% confidence interval, 0.29–2.67). Postpartum follow-ups via telephone surveys revealed that these patients remained asymptomatic and had low rates of family contacts acquiring the disease, but their adherence to social distancing guidelines waned during the 2-week postpartum period. Review of inpatient and emergency department records revealed low rates of hospital readmission. CONCLUSION: Most of the pregnant patients who screened positive for COVID-19 are asymptomatic and do not go on to develop clinically significant infection after delivery. Routine surveillance of these patients after hospital discharge appears to be sufficient.