Comparison of gestational diabetes mellitus and pre-eclampsia in women with high hemoglobin in the first trimester of pregnancy: A longitudinal study

Objective: To determine the association between high hemoglobin with gestational diabetes mellitus (GDM) and preeclampsia in pregnant women in the first trimester. Methods: This cohort study was conducted among 973 pregnant women who started their antenatal booking in the first trimester (first 14 weeks of gestation). Women with first-visit high Hb levels (> 12.5 g/L) on first visit of the pregnancy period were selected as the study group and were compared with those who had normal Hb value (< 12.5 g/L) as controls. Adverse pregnancy outcomes including preeclampsia and GDM were compared between the two groups. Results: Complete obstetric records of 448 women with high Hb levels and 486 women with normal Hb levels were studied. The follow up showed that the women with high Hb levels had significantly higher rates of preeclampsia and GDM than those with normal Hb levels; the risks were 5.4 (95% cl; 2.8 to 10.5) and 3.7 (95%cl; 2.2 to 6.4), respectively. Conclusion: This study found that high Hb in the first trimester is associated with higher risk of subsequent preeclampsia and gestational diabetes mellitus (GDM).