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

Abstract

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.

Keywords: COVID-19; SARS-CoV-2; lung ultrasound; pregnancy; universal screening.