Hb

This large hospital-based retrospective study examined the relationship between early pregnancy hemoglobin (Hb) levels and the risks of gestational diabetes mellitus (GDM), pre-eclampsia (PE), and preterm birth in 21,577 singleton pregnancies. Higher Hb levels in early pregnancy were associated with an increased risk of GDM and PE (OR: 1.27 for Hb 130-149 g/L; OR: 2.06 for Hb ≥ 150 g/L), while lower Hb levels (<110 g/L) were associated with an increased risk of preterm birth. Conversely, high Hb levels were linked to a reduced risk of preterm birth (OR: 1.30 for Hb 130-149 g/L; OR: 2.38 for Hb ≥ 150 g/L). In women with a BMI < 24 kg/m2, high Hb levels predicted higher GDM risk and lower preterm birth risk, whereas in women with a BMI ≥ 24 kg/m2, high Hb levels were associated only with increased GDM risk (OR: 2.33 for Hb > 150 g/L). These findings suggest that early pregnancy Hb levels can serve as a predictive marker for GDM, PE, and preterm birth, with varying effects based on maternal BMI.