Association of SARS-CoV-2 placental histopathology findings with maternal–fetal comorbidities and severity of COVID-19 hypoxia

Abstract

Objective

SARS-CoV-2 is known to impact multiple organ systems, with growing data to suggest the potential for placental infection and resultant pathology. Understanding how maternal COVID-19 disease can affect placental histopathology has been limited by small study cohorts with mild disease, review by multiple pathologists, and potential confounding by maternal–fetal comorbidities that can also influence placental findings. This study aims to identify pathologic placental findings associated with COVID-19 disease and severity, as well as to distinguish them from changes related to coexisting maternal–fetal comorbidities.

Methods

This is an observational study of 61 pregnant women with confirmed SARS-CoV-2 infection who delivered and had a placental histological evaluation at NYU Langone Health between March 19, 2020 and June 30, 2020. Primary outcomes were the prevalence of placental histopathologic features and their association with maternal–fetal comorbidities and severity of COVID-19 related hypoxia. Analysis was performed using Fisher’s exact test and t-test with p < 0.05 considered significant.

Results

Sixty-one placentas were included in the study cohort, 71% from pregnancies complicated by at least one maternal–fetal comorbidity. Twenty-five percent of placentas were small for gestational age and 77% exhibited at least one feature of maternal vascular malperfusion. None of the histopathologic features in the examined placentas were associated with the presence of any specific maternal–fetal comorbidity. Thirteen percent of the cohort required maternal respiratory support for COVID-19 related hypoxia. Villous trophoblast necrosis was associated with maternal supplemental oxygen requirement (67 vs. 33%, p = 0.04) and intubation (67 vs. 33%, p = 0.01).

Conclusion

In pregnancies complicated by COVID-19 disease, there was a high prevalence of placental histopathologic changes identified, particularly features of maternal vascular malperfusion, which could not be attributed solely to the presence of maternal–fetal comorbidities. The significantly increased prevalence of villous trophoblast necrosis in women needing respiratory support suggests a connection to the severity of COVID-19 illness.

Keywords:

• COVID-19
• histopathology
• placenta
• SARS-CoV-2
• hypoxia

Disclosure statement

The authors report no conflicts of interest.