The Association Between High Hemoglobin Levels and Pregnancy Complications, Gestational Diabetes and Hypertension, Among Palestinian Women

Introduction: 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 Palestinian 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 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 Palestinian women visiting prenatal clinics in Palestine. Methods: Medical records (N=5263) were reviewed for singleton pregnancies who had their first maternity care clinic visit (6-13 GW) at primary healthcare centers of the Palestinian Ministry of Health in the north of the West Bank in 2018 and 2019. Women were excluded if they had FBS ≥92 mg/dl, SBP ≥140 mmHg, DBP ≥90 mmHg, ultrasound-based gestational age >13 weeks, or who were previously diagnosed with diabetes mellites, GDM, hypertension, GH, taking drugs for these conditions, or were smoking during pregnancy. Hb levels in g/dl were divided to low (<11.0), normal (11-12.49), and high (≥12.5). The associations between high hemoglobin levels and pregnancy complications in pregnant women were assessed by calculating the odds ratios (OR) and their 95% confidence intervals (CIs) using logistic regression. P-values of <0.05 were considered significant. Results: The final number of eligible records was 2565. Pregnant women with high Hb levels in the first trimester were at higher risk of high FBS (≥126 mg/dl; OR=2.99, 95%CI, [1.675-5.368]) and high systolic blood pressure (≥140 mmHg; OR=3.048, 95%CI, [1.252-7.421]) at 24 GW. Gravidity was significantly associated with decreased risk of high FBS (OR=0.838, 95%CI [0.704-0.991]). Conclusion: Our findings suggest that Hb level at registration could be utilized in predicting the risk of GDM and HP among Palestinian women who never had a previous history of these conditions. The results of this study could have important clinical implications for early screening, which could improve preventive and curative health services to promote the health of pregnant women and children.