This is the first study to investigate the effects on gestation of the timing for a positive PCR test for SARS-CoV-2, preconception or during each trimester of pregnancy.
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Women at highest risk for pregnancy complications are those who test PCR+ for SARS-CoV-2 viral RNA preconception or during the first trimester of pregnancy.
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Features of maternal vascular malperfusion and accelerated villous maturation were prominent findings in the histopathology of placentas from women tested PCR+ for SARS-CoV-2 RNA, especially before pregnancy or during the first trimester.
Abstract
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 (TC) 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.