The association between high hemoglobin levels and pregnancy complications, gestational diabetes and hypertension

Gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) are the principal causes of maternal morbidity and mortality. The maternal morbidity and mortality burden for women is relatively high, suggesting a substandard quality of care. Therefore, an early diagnosis of GDM and gestational hypertension (GH) can improve prenatal care for pregnant women and improve pregnancy outcomes. Previous studies demonstrated that elevated Hb levels in the first trimester indicate possible pregnancy complications and should not only be considered as good iron status. However, ethnic differences could play a role in determining the magnitude of the association. We hypothesized that high Hb levels (≥12.5 g/dl) in the first trimester (6-13 gestational weeks, GW) are associated with an increased risk of fasting blood sugar (FBS) ≥126 mg/dl, systolic blood pressure (SBP) ≥140 mmHg, and diastolic blood pressure (DBP) ≥90 mmHg among pregnant women visiting prenatal clinics.