α-thalassaemia trait and gestational diabetes mellitus in Hong Kong

Aims/hypothesis. The purpose of this study was to examine the association between maternal alpha -thalassaemia trait and the occurrence of gestational diabetes mellitus in at-risk Chinese women in Hong Kong. Methods. From 3320 pregnant women who had delivered in our hospital and undergone the oral glucose tolerance test for various risk factors over a three-year period, 163 with alpha -thalassaemia trait were identified (study group). The control group consisted of 163 women chosen from the next patient that was matched for maternal age and parity, following each index case. Comparison was made in the incidence of gestational diabetes mellitus defined by the World Health Organisation criteria, obstetric complications, and perinatal outcome. Results. The incidence of gestational diabetes mellitus was higher in the study group (62.0% vs 14.7%, p < 0.0001) which had a higher pre-pregnancy body mass index and lower haemoglobin concentrations. Although more patients in the study group had risk factors (41.7% vs 26.4%, p = 0.003), there was no difference in the pregnancy outcome or perinatal complications. Among the gestational diabetic women, those with ct-thalassaemia trait were considerably younger and their infants had lower body mass index but there was no significant difference in the outcome. On multiple logistic regression analysis, the alpha -thalassaemia trait remained an important factor in the diagnosis of gestational diabetes (OR 11.74, 95% CI 6.37-21.63). Conclusion/interpretation. Among women at risk of gestational diabetes, the presence of the ct-thalassaemia trait is an additional risk factor for gestational diabetes mellitus.