Clinical factors in SARS-CoV-2 antibody response in unvaccinated mothers

Understanding the clinical factors influencing the SARS-CoV-2 antibody response during and after pregnancy is critical for optimizing maternal care and vaccination strategies. This prospective cohort study aimed to evaluate associations between maternal clinical characteristics and SARS-CoV-2-specific IgG and IgA antibody levels at delivery and 42 days postpartum in unvaccinated pregnant women.

A total of 387 pregnant women with confirmed SARS-CoV-2 infection during pregnancy were included. SARS-CoV-2 infection was confirmed using real-time RT-PCR. Clinical data, including age, body mass index (BMI), smoking status, pre-existing morbidities, and obstetric complications, were recorded. SARS-CoV-2-specific IgG and IgA antibodies were quantified using ELISA at delivery and 42 days postpartum.

Higher preconception BMI significantly correlated with increased odds of detecting IgG and IgA antibodies at both delivery and postpartum assessments (p<0.05), independently of maternal age and chronic diseases. Women without chronic systemic diseases exhibited lower antibody levels at delivery, whereas smokers had significantly lower odds of IgG antibody presence at delivery. Additionally, pre-existing cardiovascular diseases were associated with reduced antibody presence at six weeks postpartum. Other clinical parameters did not show significant associations.

Preconception BMI and pre-existing systemic diseases may modulate SARS-CoV-2 antibody responses in pregnant women. These clinical factors should inform assessments of maternal and neonatal infection risks and guide vaccination strategies in pregnant populations. Further research is needed to elucidate the mechanisms underlying these associations.