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SARS-CoV-2 Variant-Related Abnormalities Detected by Prenatal MRI: A Prospective Case-Control Study
24 Pages Posted: 25 Oct 2022
More...Abstract
Background: There are known complications for fetuses after infection with SARS-CoV-2 during pregnancy. However, previous studies of SARS-CoV-2 in pregnancy have largely been limited to histopathologic studies of placentas and prenatal studies on the effects of different SARS-CoV-2 variants are scarce to date. To investigate the effects of SARS-CoV-2 variants on the placenta and fetus, we aimed to investigate fetal and extra-fetal structures using prenatal MRI.
Methods: For this prospective case-control study, two obstetric centers consecutively referred pregnant women for prenatal MRI after confirmed SARS-CoV-2 infection.Forty-three prenatal MRI examinations were included after confirmed infection with SARS-CoV-2 and matched 1:1 with 43 control cases with respect to sex, MRI field strength, and gestational age (average deviation 1·7 ± 1·6 days).Where available, the pathohistological examination of the placenta was included in the analysis.In prenatal MRI, the shape and thickness of the placenta, possible lobulation, and vascular lesions were quantified. Fetuses were scanned for organ or brain abnormalities.
Findings: Of the 43 included cases after SARS-CoV-2 infection, 25 (58%) were infected with pre-Omicron variants and 18 (42%) with Omicron. Prenatal MRIs were performed on an average of 144 ± 70·7 days after the first positive PCR test.Both pre-Omicron (P=·002) and Omicron (P=·016) groups showed abnormalities in form of a globular placenta compared to control cases. In addition, placentas in the pre-Omicron group were significantly thickened (Mean Diff. 7·32mm, 95% CI 2·05 to 12·59, P=·009), and showed significantly more frequent lobules (P=·031), and hemorrhages (P=·003).Fetal growth restriction (FGR) was observed in 28% (P=·004) in the pre-Omicron group.
Interpretation: SARS-CoV-2 infections in pregnancy can lead to placental lesions based on vascular events, which can be well visualized on prenatal MRI. Pre-Omicron variants cause greater damage than Omicron sub-lineages in this regard.
Funding Information: Vienna Science and Technology Fund.
Declaration of Interests: The authors declare no conflict of interest.
Ethics Approval Statement: The institutional review board of the Medical University of Vienna approved this prospective study (Ethics Committee number 2306/2020). Written informed consent was obtained before study inclusion.
Keywords: COVID-19, SARS-CoV-2, COVID-19 during pregnancy, Omicron, variants, prenatal MRI, placenta, vascular
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