Blood test may identify stillbirth, placentitis in women with COVID-19

A blood test may identify pregnant women with COVID-19 who are at higher risk for stillbirth and placentitis, according to a small observational study published in Placenta.

According to the researchers, recent studies have demonstrated a higher risk for stillbirth among women with COVID-19, which has been associated with COVID placentitis.

“Right now, we don’t know if there’s placentitis until after [delivery],” Leena B. Mithal, MD, an assistant professor of pediatric infectious diseases at Northwestern University Feinberg School of Medicine and an attending physician at Ann & Robert H. Lurie Children’s Hospital of Chicago, said in a university press release. “We’re laying groundwork for further studies so that in the future, people who are diagnosed with COVID during pregnancy may be able to get a test that will help identify pregnancies that may be at higher risk of stillbirth or fetal distress.”

Mithal and colleagues matched patients infected with SARS-CoV-2 between April 2020 and January 2021 who delivered at Northwestern Medicine Prentice Women’s Hospital in Chicago. They included six women with COVID placentitis confirmed through pathologic exam and maternal plasma samples and 12 without COVID placentitis.

Clinical samples were tested with quantitative reverse transcription polymerase chain reaction to identify viral RNA — or viremia — in women’s blood.

Among the patients with placentitis, one had asymptomatic SARS-CoV-2 infection, four had mild infections and one had moderate infection. There was one stillbirth in the placentitis group.

Two women with placentitis were viremic, including the patient who had a stillbirth, while viremia was not detected in the group without placentitis.

“Given the wide clinical availability of SARS-CoV-2 PCR testing, viremia could represent a target for screening pregnant patients with SARS-CoV-2 infection for potential COVID placentitis and risk stratification of stillbirth,” Mithal and colleagues wrote.

They cautioned that potential false positives and transient viremia at the time of SARS-CoV-2 infection may limit their findings.

The researchers suggested the best way to protect the parent and baby against adverse outcomes is to get vaccinated.

“We don’t know why viremia does or doesn’t affect some people, but the vaccine does seem to protect against severe complications,” Mithal said.

References:

• Blood test may indicate higher risk pregnancies in patients with COVID-19. https://www.eurekalert.org/news-releases/946693. Published March 16, 2022. Accessed March 29, 2022.
• Mithal LB, et al. Placenta. 2022;doi:10.1016/j.placenta.2022.03.003.