The association between maternal anemia and preterm birth: A case-control study

Introduction: Preterm birth (PTB), defined as birth before 37 weeks of gestation, remains a global public health challenge associated with neonatal morbidity and mortality. Maternal anemia, characterized by low hemoglobin levels, is prevalent in many low- and middle-income countries, including Pakistan. Methodology: A case-control study was conducted at Swat Medical College and Women Hospital Mardan, Pakistan, from June 2022 to June 2023. Medical records of 1000 pregnant women (500 cases of PTB and 500 controls of term births) were reviewed. Maternal anemia, defined as hemoglobin levels below 11 g/dL, was assessed along with demographic variables, pregnancy history, and maternal complications. Logistic regression analysis adjusted for potential confounders was performed to determine the association between maternal anemia and PTB. Results: Maternal anemia was significantly associated with an increased risk of PTB (adjusted odds ratio OR = 2.50; 95% confidence interval CI: 1.80-3.50; p < 0.001). Other significant risk factors included previous PTB (adjusted OR = 2.20; 95% CI: 1.50-3.20; p < 0.001), multiparity (adjusted OR = 1.50; 95% CI: 1.10-2.00; p = 0.01), preeclampsia (adjusted OR = 3.00; 95% CI: 2.20-4.20; p<0.001), and gestational diabetes (adjusted OR = 2.00; 95% CI: 1.50-2.70; p<0.001). Demographic factors such as maternal age, education, residence, and pre-pregnancy BMI did not show significant associations with PTB. Conclusion: Maternal anemia emerges as a significant risk factor for PTB in Pakistan. Early detection and management of anemia during pregnancy are crucial to reducing the burden of PTB and its associated adverse outcomes.