Impacts of β‐thalassemia/hemoglobin E disease on pregnancy outcomes.

Objective: To compare obstetric outcomes between women with β‐thalassemia/hemoglobin E (β‐thal/HbE) disease and those of low‐risk pregnancies, and also between the two subgroups, β‐thal0/HbE and β‐thal+/HbE disease. Methods: A retrospective cohort study was undertaken on pregnant women with β‐thal/HbE disease and low‐risk pregnancies, which were randomly selected with a case‐to‐control ratio of 1:10. Results: Pregnancies with β‐thal/HbE disease were identified in 0.19% of 59 152 pregnancies, including 104 women in the study group and 1040 women in the control group. The mean gestational age and mean birth weight were significantly lower in the study group. The prevalence of fetal growth restriction, preterm birth and low birth weight were significantly increased in the study group based on both univariate and multivariate analysis. The impacts were more striking in the β‐thal0/HbE subgroup than in the β‐thal+/HbE subgroup. The cesarean rate was significantly higher in the study group. No maternal death or serious complication was found in this cohort. Conclusion: Based on this cohort, the largest ever published, β‐thal/HbE disease is significantly associated with increased incidence of fetal growth restriction, preterm birth and low birth weight. The impacts were more pronounced in the β‐thal0/HbE subgroup. Pregnancy may be relatively safer for women with β‐thal/HbE disease. Synopsis: β‐thal/HbE disease is associated with increased incidence of risk of fetal growth restriction and preterm birth. The adverse impact appears to be more pronounced with β‐thal0/HbE disease. [ABSTRACT FROM AUTHOR]