Comparing Two Testing Strategies: Universal versus Symptomatic SARS-CoV-2 Testing in Obstetric Patients

Understanding how to best test pregnant individuals for SARS-CoV-2 remains a challenge. Prior research has shown that pregnancy can increase the risk of severe illness from SARS-CoV-2, but the best testing strategy is unclear. No prior work had resolved whether testing only those with symptoms is sufficient or if universal testing is more effective. This gap motivated a study to compare two testing approaches in obstetric care. The study aimed to clarify how these strategies affect case detection and maternal-neonatal outcomes. It was already known that testing strategies vary widely across institutions. However, the impact of these variations on clinical outcomes was not well established. This study focused on a specific geographic region to control for external factors. The goal was to provide evidence to guide testing decisions in obstetric settings.

The study aimed to compare two SARS-CoV-2 testing strategies in pregnant individuals: universal testing and symptomatic testing. The researchers wanted to determine if one approach led to better clinical outcomes. They focused on two large academic centers in Northeast Ohio. The primary outcome was the positivity rate among symptomatic patients. A secondary outcome was the rate of SARS-CoV-2 positivity in newborns. The study also aimed to assess the added value of universal testing. The researchers hypothesized that universal testing might detect more cases than symptomatic testing. They sought to understand if this approach affected maternal and neonatal outcomes. The study design allowed for a direct comparison of the two strategies.

The study used a retrospective cohort design at two academic medical centers. Data were collected from March 2020, when symptomatic testing began at both institutions. Pregnant individuals under 18 years were excluded. The primary outcome was the positivity rate in symptomatic patients. A coprimary outcome was the additional positivity rate from universal testing at one institution. Secondary outcomes included neonatal positivity rates. Statistical analysis included the Mann-Whitney U test for continuous variables. Chi-square and Fisher’s exact tests were used for proportions. The researchers compared the number of tests and positive results between the two strategies. They also examined maternal and neonatal outcomes across the groups.

At MetroHealth, 144 symptomatic pregnant individuals were tested, with 27 positive results (18.7% positivity rate). At University Hospitals, 392 symptomatic individuals were tested, with 67 positive results (17.0% positivity rate). University Hospitals also performed 2,870 universal tests on asymptomatic individuals, with 30 positive results (1.0% positivity rate). No infants tested positive for SARS-CoV-2 in the study. All cases of maternal critical illness occurred in symptomatic patients. The two testing strategies showed similar clinical performance. Universal testing identified only a small number of additional cases. The results suggest that both approaches had comparable outcomes in this region.

The authors found that both universal and symptomatic testing strategies had similar clinical performance in obstetric patients. They noted that universal testing detected only a small number of additional SARS-CoV-2 cases. No infants in the study tested positive for the virus. All maternal critical illnesses occurred in symptomatic patients. The researchers concluded that there is no clear evidence to prefer one strategy over the other. They emphasized that testing strategy did not affect maternal or neonatal outcomes. The study did not support a strong recommendation for universal testing in this population. The authors suggested that further research may be needed to clarify the best approach.