Placental histopathology findings suggest increased antenatal surveillance is necessary for women with COVID-19, according to a report in the American Journal of Clinical Pathology.
A study of 16 placentas from women with moderate to severe SARS-CoV-2, one in second-trimester (foetal demise), and the 15 in third-trimesters were compared to historical controls and between placentas from women with a history of melanoma.
Four patients had COVID-19 25-34 days prior to delivery, two were diagnosed six and seven days prior to delivery, and the remaining 10 were diagnosed on presentation to labour and delivery. Ten of 16 patients were symptomatic, two requiring oxygen, none were intubated. All infants were negative for SARS-CoV-2.
Placental findings from COVID-19 mothers included; small for gestational age (N=5), one significantly, large for gestational age (N=1). Features of maternal vascular malperfusion (MVM) were present in 12/15 cases, significantly higher than melanoma (59/215; P=.001), and all controls (7,754/17,479; P=.046). Features included villous infarctions, villous agglutination and accelerated villous maturation. Decidual arteriopathy occurred in 7/15 cases. No pathognomonic features were identified.
The authors say the increased rates of MVM and intervillous thrombi suggest a common theme of abnormal maternal circulation, as well as an increased incidence of chorangiosis.