SARS‐CoV‐2—Placental effects and association with stillbirth

Abstract

SARS‐CoV‐2 has had a significant impact on pregnancy outcomes due to the effects of the virus and the altered healthcare environment. Stillbirth has been relatively hidden during the COVID‐19 pandemic, but a clear link between SARS‐CoV‐2 and poor fetal outcome emerged in the Alpha and Delta waves. A small minority of women/birthing people who contracted COVID‐19 developed SARS‐CoV‐2 placentitis. In many reported cases this was linked to intrauterine fetal death, although there are cases of delivery just before imminent fetal demise and we shall discuss how some cases are sub‐clinical. What is surprising, is that SARS‐CoV‐2 placentitis is often not associated with severe maternal COVID‐19 infection and this makes it difficult to predict. The worst outcomes seem to be with diffuse placental disease which occurs within 21 days of COVID‐19 diagnosis. Poor outcomes are often pre‐dated by reduced fetal movements but are not associated with ultrasound changes. In some cases, there has also been maternal thrombocytopenia, or coagulation abnormalities, which may provide a clue as to which pregnancies are at risk of fetal demise if a further variant of concern is to emerge. In future, multidisciplinary collaboration and cross‐boundary working must be prioritised, to identify quickly such a phenomenon and provide clinicians with clear guidance for reducing fetal death and associated poor outcomes. While we wait to see if COVID‐19 brings a future variant of concern, we must focus on appropriate future management of women who have had SARS‐CoV‐2 placentitis. As a placental condition with an infectious aetiology, SARS‐CoV‐placentitis is unlikely to recur in a subsequent pregnancy and thus a measured approach to subsequent pregnancy management is needed.