Outcomes of universal SARS-CoV-2 testing program in pregnant women admitted to hospital and the adjuvant role of lung ultrasound in screening: a prospective cohort study

Background The emerging evidence for the asymptomatic carriers of SARS-CoV-2 infection emphasized the critical need for universal screening of pregnant women. Objectives This study aimed to present the prevalence of overall and asymptomatic SARS-CoV-2 infection rates in pregnant women admitted to the hospital, and assess the diagnostic accuracy of maternal symptoms and lung ultrasound (LUS) findings in detecting the infection. Patients and methods This prospective cohort study was conducted at a single tertiary center in Istanbul, Turkey, for a month period starting from 27 April 2020. Women with a confirmed pregnancy regardless of the gestational week admitted to the obstetric unit with any indication were consecutively underwent LUS and PCR testing for SARS-CoV-2. Results A total of 296 patients were included for the final analysis. The universal screening strategy diagnosed 23 pregnant women (7.77%) with SARS-CoV-2 infection. The rate of symptomatic and asymptomatic patients diagnosed with SARS-CoV-2 was found as 3.72% (n = 11) and 4.05% (n = 12), respectively. Four of nine women who underwent a second testing for SARS-CoV-2 upon abnormal LUS findings were found positive eventually (17.4%,n = 4/23). The asymptomatic pregnant women with LUS score of 1 and those with normal LUS findings were considered as likely to be normal. Symptomatic patients with LUS score of 1 and those with score of 2 or 3 were considered as abnormal. On a secondary diagnostic performance analysis, the positive predictive value and the sensitivity were found as 44% and 47.8% for the triage based on maternal symptoms and, 82.3% and 60.9% for the triage based on LUS, respectively. Conclusion A one-month trial period of universal testing for SARS-CoV-2 infection with RT-PCR in pregnant women who admitted to the hospital showed an overall and asymptomatic infection diagnose rate of 7.77% and 4%, respectively. Using lung ultrasound was found more predictive in detecting the infection than the use of symptomatology solely.