Clinical and genetic predictors of great obstetrical syndromes following SARS-CoV-2 infection: the role of somatic background and the VDR gene rs2228570 polymorphism

Introduction. SARS-CoV-2 infection during gestation is associated with dramatically increased incidence of major obstetrical syndromes (МOS). Aim: to evaluate a combined impact of COVID-19 contracted during the first or second trimester of pregnancy, baseline somatic history as well as the VDR gene rs2228570 polymorphism on МOS risk manifestation. Materials and Methods. This study involved 299 pregnant women. Initially, the participants were allocated into two groups: the primary cohort comprised patients who underwent SARS-CoV-2 infection during the first or second trimester of gestation (Group 1, n = 146), while the control group consisted of pregnant women with no history of infectious pathology (Group 2, n = 153). Based on the pattern of gestational outcomes, the cohorts were stratified into subgroups: 1a (МOS manifestation, n = 40) and 1b (physiological outcomes, n = 106) within the infected cohort; 2a (МOS presence, n = 16) and 2b (uncomplicated gestation, n = 137) within the control group. Molecular genetic testing of the VDR gene rs2228570 locus was performed by real-time PCR, followed by statistical data processing. Results. COVID-19 contracted during pregnancy increased the overall МOS incidence by 2.6-fold (p = 0.0002), with predominance of severe preeclampsia (p = 0.018; odds ratio (OR) = 5.55). The manifestation of placenta-associated complications was linked to the presence of respiratory (p = 0.018) and digestive (p = 0.022) system diseases. The VDR gene rs2228570 locus did not influence the risk of SARS-CoV-2 infection during gestation (p = 0.297) but acted as a significant МOS predictor of placental decompensation in the post-COVID period (p = 0.0007). The presence of the AG genotype increased the risk of MOS development by 4.2-fold (95 % confidence interval (CI) = 1.47–11.81; p = 0.0056), whereas the GG genotype elevated it by 7.3-fold (95 % CI = 2.22–23.93; p = 0.0009). Conclusion. The VDR gene rs2228570 polymorphism does not determine the risk of SARS-CoV-2 infection during pregnancy; however, under post-infectious conditions, the carriage of the G allele may serve as МOS predictor developing in concomitant respiratory and digestive system diseases.