Screening for β-Thalassemia Trait in Pregnant Women With Microcytic Hypochromic Anemia and Its Impact on Pregnancy Outcomes.

Background Thalassemia is a common autosomal recessive hemoglobinopathy and a major public health concern in India. In pregnancy, β-thalassemia trait often presents as microcytic hypochromic anemia and may mimic iron deficiency anemia, leading to misdiagnosis and inappropriate management. Early and accurate differentiation is essential to prevent unnecessary iron therapy and reduce adverse maternal and neonatal outcomes. The study was designed to evaluate the prevalence, diagnostic differentiation, and pregnancy outcomes associated with β-thalassemia trait in this population. Methods This prospective observational study was conducted over a period of 12 months at a tertiary care center in North India. A total of 171 pregnant women with hemoglobin ≤11 g/dL and microcytic hypochromic anemia were enrolled. All participants underwent complete hemogram, peripheral smear examination, serum ferritin estimation, and calculation of discriminant indices, including the Mentzer index, the Shine and Lal index, and the RDW index. Patients with normal or elevated serum ferritin levels and indices suggestive of β-thalassemia underwent confirmatory testing using high-performance liquid chromatography and hemoglobin H preparation to rule out alpha thalassemia. Maternal outcomes such as mode of delivery, obstetric complications, and transfusion requirements, along with neonatal outcomes including birth weight, gestational age, Apgar score, and NICU admission, were recorded. Results Iron deficiency anemia was observed in 150 (87.7%) women, while β-thalassemia trait was identified in 21 (12.3%). Women with β-thalassemia trait had significantly lower hemoglobin levels (7.90 ± 1.36 vs 9.05 ± 0.93 g/dL), lower MCV and MCH values, and higher RBC counts (p = 0.001). Discriminant indices showed excellent diagnostic performance, with the Mentzer index, RDW index, and MCH demonstrating very high accuracy. Serum ferritin levels were <15 ng per ml in all iron deficiency anemia cases and >15 ng per ml in 95.2% of β-thalassemia cases (p = 0.001). Severe anemia was significantly more frequent in the β-thalassemia group (33.3% vs 1.3%) along with a higher requirement for packed red cell transfusion (42.9% vs 13.3%; p = 0.003). Obstetric complications such as severe preeclampsia, postpartum hemorrhage, and ICU admission were significantly more common in β-thalassemia trait. Neonatal outcomes were significantly worse, with higher rates of preterm birth (38.1% vs 4.1%), intrauterine growth restriction (47.6% vs 4.1%), low birth weight (61.9% vs 4.8%), and NICU admission (89.4% vs 15.8%) (p = 0.001). Conclusion β-thalassemia trait contributes significantly to anemia in pregnancy and is associated with increased maternal and neonatal morbidity. Simple hematological indices combined with serum ferritin estimation provide reliable and cost-effective screening tools for differentiating β-thalassemia trait from iron deficiency anemia. Early detection and appropriate management may help improve pregnancy outcomes.