SARS-CoV-2 in first trimester pregnancy – does it affect the fetus?

Background Several viral infections are known to be harmful to the fetus in the first trimester of pregnancy and can cause increased nuchal translucency thickness and pregnancy loss. Currently, no evidence exists regarding possible effects of SARS-CoV-2 in first trimester pregnancies. Methods Cohort 1 included pregnant women with a double test taken between Feb. 17 and Apr. 23, 2020, during the SARS-CoV-2 epidemic peak in Denmark. The double test was taken as part of the first trimester risk assessment. Cohort 2 included women with a first trimester pregnancy loss before double test. Serum from the double test or from a blood sample, in case of pregnancy loss, was analyzed for SARS-CoV-2 antibodies. The results were correlated to the nuchal translucency thickness and the number of pregnancy losses. Results In total, 1,019 pregnant women with double test and 36 women with pregnancy loss participated in the study. Thirty (2.9%) women had SARS-CoV-2 antibodies in the serum from the double test. All women with pregnancy loss prior to the double test were negative for SARS-CoV-2 antibodies. There were no significant differences in nuchal translucency thickness for women testing positive (n=14) versus negative (p=0.20) or grey zone (n=16) versus negative (p=0.28). In total, 54 women experienced a pregnancy loss of whom two had grey zone or positive SARS-CoV-2 antibodies. Conclusion Maternal SARS-CoV-2 infection did not seem harmful in first trimester pregnancies. Infection had no effect on the nuchal translucency thickness and women with SARS-CoV-2 antibodies were not overrepresented among women with pregnancy loss.