Seroprevalence of SARS-CoV-2 antibodies among first-trimester pregnant women during the second wave of the pandemic in India

Objective Data on the immune response to SARS-CoV-2 during pregnancy are lacking and the potential role and effect of SARS-CoV-2 vaccination in pregnancy is yet to be completely investigated. Method This is a cross-sectional observational study wherein pregnant women were tested for SARS-CoV-2 immunoglobulin M and immunoglobulin G levels, irrespective of their infective status or presence or symptomatology. Result Of the 220 pregnant women tested, 160 (72.7%) were SARS-CoV-2 IgG positive, 37 (16.8%) were SARS-CoV-2 IgM positive and 27 (16.9%) were both IgG and IgM positive. The average antibody titer found was 10.49 BAU/ml (+/- 14.0) and 0.6 (+/- 0.55) for anti-SARS-CoV-2 IgG and IgM non neutralizing antibodies respectively. ROC analysis for SARS-CoV-2 IgG positivity showed a cut-off value of 1.19 with a sensitivity of 99.3% (0.99 AUC, 95% CI) and specificity of 98.3% (0.99 AUC, 95% CI), respectively. Similarly, ROC analysis for SARS-CoV-2 IgM positivity showed a cut-off value of 1 with a sensitivity of 97.3% (0.99 AUC, 95% CI) and specificity of 98.9% (0.99 AUC, 95% CI), respectively. Conclusion First trimester sero-molecular screening suggests a high prevalence of COVID antibodies in the study population of pregnant women in the first trimester, without the patients being symptomatic.