Histopathologic evaluation of placentas after diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection

BACKGROUND: The impact of maternal severe acute respiratory syndrome coronavirus 2 infection on placental histopathology is not well known. OBJECTIVE: To determine if any significant placental histopathologic changes occur after the diagnosis of severe acute respiratory syndrome coronavirus 2 infection during pregnancy and whether these changes are correlated with the presence or absence of symptoms associated with the infection. STUDY DESIGN: A retrospective cohort study of women diagnosed as having severe acute respiratory syndrome coronavirus 2 infection who delivered at a single center from April 9, 2020 to April 27, 2020, and had placental specimens reviewed by the Department of Pathology. Women with singleton gestations and laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection were eligible for inclusion. Historical controls selected from a cohort of women who delivered 6 months before the study period were matched in a 1:1 fashion by weeks of gestation at delivery. Histopathologic characteristics were evaluated in each placenta, and the incidence of these findings was compared between placentas of those who received a diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection and historical controls, and between placentas from patients with or without typical symptoms related to the infection. Statistical analyses included the use of Wilcoxon rank-sum test and Fisher's exact test for the comparison of categorical and continuous variables. Statistical significance was defined as a P value of <.05. RESULTS: A total of 50 placentas after the diagnosis of maternal severe acute respiratory syndrome coronavirus 2 infection and 50 historical controls were analyzed. Among the placentas from patients diagnosed with severe acute respiratory syndrome coronavirus 2 infection, 3 (6%) were preterm (33 3/7, 34 6/7, and 36 6/7 weeks of gestation), 16 (32%) were from patients with typical symptoms related to the infection, and 34 (68%) were from patients without typical symptoms related to the infection. All patients had received a diagnosis of severe acute respiratory syndrome coronavirus 2 infection in the third trimester. Decidual vasculopathy was not visualized in any of the placentas from patients diagnosed as having severe acute respiratory syndrome coronavirus 2 infection. There was no statistically significant difference in placental histopathologic characteristics between the groups. Severe acute respiratory syndrome coronavirus 2 test results for all neonates at 24 hours of life were negative. CONCLUSION: Based on the results of this study, there are no significant placental histopathologic changes that occur after the diagnosis of severe acute respiratory syndrome coronavirus 2 infection in women during the third trimester of pregnancy compared with a gestational age-matched historical control group. Similar incidences of histopathologic findings were also discovered when comparing placentas from patients with severe acute respiratory syndrome coronavirus 2 infection with or without the presence of symptoms typically related to the infection.