Miscarriage Trends and Blood Group Associations During the COVID-19 Pandemic: A Comparative Study in Ramsar, Iran.

Background: The COVID-19 pandemic has placed significant physiological, physical, and psychological burdens on populations worldwide. Childbearing, as a fundamental aspect of human life, can be negatively affected during such crises. This study aimed to evaluate the impact of the COVID-19 pandemic on miscarriage rates and to investigate the potential association between spontaneous abortions and maternal blood groups. Materials and Methods: A retrospective analytical cross-sectional study was conducted using 8,613 hospital records from two healthcare centers in Ramsar and Tonekabon, Iran. Miscarriage rates were analyzed relative to total delivery requests during the pre-pandemic (2017-2019) and pandemic (2020-2022) periods. In the second phase, unexplained spontaneous abortions were examined in relation to maternal ABO and the Rhesus factor (Rh) blood groups across both periods. Results: The analysis revealed a significant increase in miscarriage rates during the pandemic, despite a general decline in delivery requests. In the study sample, blood group distribution was A: 29.86%, B: 21.53%, O: 43.06%, and AB: 5.56%, while 9.72% were Rh-negative and 90.28% Rh-positive. Although abortions appeared more common in certain blood groups (notably B and O), statistical analysis showed no significant association between miscarriage and maternal individual blood types before or during the pandemic. Conclusions: The findings suggest that physiological and psychological stressors during the pandemic may have contributed to increased miscarriage rates. Health systems should implement integrated strategies, including mental health support and enhanced prenatal care, to reduce adverse pregnancy outcomes during pandemics or similar crises.