Testing pregnant women with Covid-19 for viral RNA may identify those at risk of stillbirth and placentitis, according to results of a small study published in the journal Placenta.¹

Women who had Covid-19 during pregnancy and delivered at a hospital in Chicago, USA were included in this study. The study group was small comprising of six women with Covid placentitis confirmed on pathologic examination. Their plasma samples were also obtained. Twelve women matched for gestational age at birth and time between SARS-CoV-2 infection and delivery but without placentitis were selected as controls. The plasma samples were tested for maternal viremia (viral RNA) through quantitative RT PCR.

Of the six women with placentitis, one had asymptomatic Covid-19, one had moderate infection, while four had mild infection. There was one stillbirth in this group. Viremia was detected in two patients with placentitis, including an asymptomatic patient with stillbirth, and the other with mild symptoms who delivered a well infant. All women in the control group were negative for viral RNA.

Viremia rarely occurs in SARS-CoV-2 infection. Placentitis and stillbirth are adverse effects of Covid-19 infection during pregnancy. But these adverse outcomes are not just limited to those with severe infection. This study has demonstrated viremia in two patients with Covid placentitis, one of whom had a stillbirth. Hence, testing Covid-positive pregnant women for viremia may serve as a screening test to detect at-risk women for potential Covid placentitis and risk of stillbirth.

Reference

1. Mithal LB, et al. Low-level SARS-CoV-2 viremia coincident with COVID placentitis and stillbirth. Placenta. 2022 Mar 9;121:79-81. doi: 10.1016/j.placenta.2022.03.003.