Association of Maternal Anemia with Adverse Pregnancy Outcomes: A Prospective Cohort Study

Abstract

Background: Maternal anemia remains a common pregnancy complication and has been associated with preterm birth, low birth weight, postpartum hemorrhage, and neonatal morbidity. The strength of these associations varies according to anemia severity, gestational timing, and population characteristics. Objective: To evaluate the association between maternal anemia and adverse maternal, fetal, and neonatal outcomes among pregnant women receiving antenatal care at Government Medical College Handwara. Materials and Methods: This prospective cohort study was conducted from September 20, 2025 to September 20, 2026. Six hundred pregnant women with singleton pregnancies were followed from enrollment at or before 20 weeks of gestation until delivery and the early neonatal period. Maternal anemia was defined using trimester-specific World Health Organization hemoglobin thresholds. The primary endpoint was a composite adverse pregnancy outcome. Secondary outcomes included preterm birth, low birth weight, small for gestational age, hypertensive disorders, premature rupture of membranes, cesarean delivery, postpartum hemorrhage, blood transfusion, stillbirth, low five-minute Apgar score, and neonatal intensive care unit admission. Risk ratios and multivariable-adjusted risk ratios were estimated with 95% confidence intervals. Results: Of 600 women, 318 (53.0%) were classified as anemic and 282 (47.0%) as non-anemic. The composite adverse pregnancy outcome occurred in 145 (45.6%) anemic women and 78 (27.7%) non-anemic women (RR 1.65, 95% CI 1.32-2.06; p<0.001). Maternal anemia was associated with higher risks of preterm birth (19.2% vs. 11.0%), low birth weight (24.8% vs. 12.8%), small-for-gestational-age birth (17.3% vs. 8.9%), premature rupture of membranes (16.0% vs. 8.5%), postpartum hemorrhage (9.7% vs. 3.9%), low five-minute Apgar score (8.8% vs. 3.9%), and NICU admission (20.1% vs. 9.9%). After multivariable adjustment, anemia remained independently associated with the composite endpoint, preterm birth, low birth weight, small for gestational age, premature rupture of membranes, postpartum hemorrhage, low Apgar score, and NICU admission. A graded increase in adverse outcomes was observed with increasing anemia severity. Conclusions: Maternal anemia was associated with a substantially higher risk of adverse pregnancy outcomes, particularly preterm birth, low birth weight, small-for-gestational-age birth, postpartum hemorrhage, and neonatal morbidity. Early identification, correction of anemia, and risk-based obstetric surveillance may improve maternal and perinatal outcomes.

Keywords: maternal anemia, pregnancy, preterm birth, low birth weight, postpartum hemorrhage, neonatal intensive care, prospective cohort