Ethnic Differences in Characteristics of Women Diagnosed With Early Gestational Diabetes: Findings From the TOBOGM Study.

OBJECTIVE

To compare the prevalence and clinical characteristics of early gestational diabetes (eGDM) and associated birth outcomes among women of different ethnic groups.

METHODS

This is a secondary analysis of an international, multicenter randomized controlled trial of treating eGDM among pregnant women with GDM risk factors enrolled at < 20 weeks' gestation. GDM diagnosis was made using WHO-2013 criteria. Ethnicity was classified by self-identification. While Europids required at least one risk factor for recruitment, for others, ethnicity itself was a risk factor.

RESULTS

Among women of Europid (n = 1567), South Asian (SA: n = 971), East and South-East Asian (ESEA: n = 498), Middle Eastern (ME: n = 242), and Māori and Pasifika (MP: n = 174) ethnicities; MP (26.4%) had the highest eGDM crude prevalence compared with Europid (20.3%), SA (24.7%), ESEA (22.3%), and ME (21.1%) (P < .001). Compared with Europid, the highest eGDM adjusted odds ratio (aOR) was seen in SA (2.43 [95% CI 1.9-3.11]) and ESEA (aOR 2.28 [95% CI 1.68-3.08]); in late GDM, SA had the highest prevalence (20.4%: aOR 2.16 [95% CI 1.61-2.9]). Glucose patterns varied between ethnic groups and ESEA were predominantly diagnosed with eGDM through post-glucose load values, while all other ethnic groups were mainly diagnosed on fasting glucose values. There were no differences in the eGDM composite primary outcome or neonatal and pregnancy-related hypertension outcomes between the ethnic groups.

CONCLUSION

In women with risk factors, eGDM was most prevalent in SA and ESEA women, particularly identified by the post-glucose load samples. These findings suggest an early oral glucose tolerance test should particularly be performed in women from these ethnic groups.