The effects of preconception and early gestation SARS-CoV-2 infection on pregnancy outcomes and placental pathology

Objective: To evaluate if peri-pregnancy timing of a PCR+ test for SARS-CoV-2 RNA affects pregnancy outcomes and placental pathology. Methods: This is a retrospective cohort study conducted in a tertiary center. Pregnancy outcomes and placental pathology were compiled for women who tested positive for SARS-CoV-2 RNA from a nasopharyngeal swab assessed by RT-PCR. The population comprised four groups that were PCR+ preconception (T₀) or in the 1st (T₁), 2nd (T₂), or 3rd (T₃) trimester of pregnancy. A fifth, control group (T_C) tested PCR- for SARS-CoV-2 before delivery. Results: Seventy-one pregnancies were studied. The T₀ group exhibited lower gestational ages at delivery, had infants with the lowest birth weights, the highest rate of pregnancy loss before 20 weeks. Features of maternal vascular malperfusion and accelerated villous maturation were prominent findings in the histopathology of placentas from women PCR+ for SARS-CoV-2 RNA, especially in the T₀ and the T₁ groups. Conclusion: Women at highest risk for pregnancy complications are those who test PCR+ for viral RNA preconception or during first trimester of pregnancy.