Early pregnancy maternal hemoglobin and the risk of neonatal congenital heart disease: insights from a case-control study, Guangdong, China.

Introduction: The association between maternal hemoglobin in the first trimester (1st TRI) and the risk of neonatal congenital heart disease (CHD) remains unclear.

Methods: A case-control study was conducted involving 102 CHD neonates and 408 controls. Iron-deficiency anemia in the first trimester (1st TRI) was characterized by a hemoglobin level below 110 mg/L, in the absence of hemoglobinopathies such as thalassemias and sickle cell anemia like thalassemia or sickle cell anemia. We utilized logistic regression models to assess the association between maternal hemoglobin/iron-deficiency anemia in 1st TRI and the risk of neonatal CHD.

Results: Neonate born to mothers with iron-deficiency anemia in 1st TRI increased risks of CHD and patent ductus arteriosus compared to those in neonates born to mothers without anemia in 1st TRI (OR = 3.544, 95%CI = 1.428, 8.795; OR = 6.990, 95%CI = 1.248, 39.157, respectively). Pregnant women in the lowest hemoglobin quartile (Q1) in 1st TRI had a significantly higher risk compared to Q4 (OR = 5.365, 95% CI: 2.232-12.896). There was a dose-response relationship between lower maternal hemoglobin in 1st TRI and the increased risk of neonate CHD (P for trend < .001). The probabilities of neonates developing CHD increased as the maternal hemoglobin concentrations in 1st TRI decreased (rs = -0.614, 95% CI: -0.673, -0.555, P < .05).

Conclusion: Maternal iron-deficiency anemia in 1st TRI increased the risk of CHD in neonates. Maternal hemoglobin in 1st TRI may be a practical risk marker of neonatal CHD. Key message What is already known on this topic-Previous studies have suggested that maternal anemia may influence fetal development, but the association between first-trimester maternal hemoglobin levels and the risk of neonatal CHD has remained unclear. What this study adds-This study demonstrates that maternal iron-deficiency anemia in the first trimester is significantly associated with an increased risk of neonatal CHD, particularly PDA, and that lower maternal hemoglobin levels are positively associated with higher CHD risk. How this study might affect research, practice or policy-These findings highlight the importance of early screening and management of maternal iron-deficiency anemia, suggesting that maternal hemoglobin in the first trimester could serve as a potential risk marker for neonatal CHD, informing prenatal care strategies and public health policies.