Pregnancy outcomes among women with hemoglobin E trait

To compare the maternal and fetal outcomes between pregnant women complicated with hemoglobin E (HbE) trait and normal controls.

A retrospective cohort study was conducted by assessment of the database of maternal-fetal medicine units from January 2003 to December 2013 to identify singleton pregnant women complicated by HbE trait. Pregnancies with medical complications or fetal anomalies were excluded. The normal controls were low-risk pregnancies and were non-carrier status for thalassemia and hemoglobinopathy.

During the study period, 1073 women with HbE trait and 2146 normal controls were included. The baseline characteristics of the two groups were comparable except that the number of prenatal visit was statistically higher in study group (8.55 ± 3.03 versus 7.85 ± 4.33, p = <0.001). Most pregnancy outcomes were not significantly different. However, the rate of asymptomatic bacteriuria was minimally higher in the study group, 3.5% versus 2.3%; p = 0.042 (relative risk 1.19; 95%CI: 0.98-1.43). Note that the rates of gestational diabetes tend to be higher in the group of HbE trait (7.6% versus 6.8%), but did not reach a statistical level.

The HbE trait does not significantly increase risk of common adverse pregnancy outcomes, except for minimal increase in asymptomatic bacteriuria.