Do WHO criteria for gestational diabetes fit a rural population in Tanzania? – A follow-up study assessing mother and child health six years after a pregnancy diagnosed with gestational diabetes

Aims and Methods
In low- and middle- income countries (LMICs) consequences of gestational diabetes (GDM) is understudied. Using a prospective cohort of mothers (n = 197) and children (n = 251), from rural north-eastern Tanzania, we assessed prediabetes and type 2 diabetes (T2D) prevalence six years after a pregnancy with/without GDM.

Results
The prevalence of prediabetes (49.4 % vs. 46.4 %) or T2D (20.0 % vs. 16.1 %), p ≥ 0.36, based on fasting plasma glucose (FPG) or HbA1c levels (prediabetes: 16.9 % vs. 13.8 % and T2D 1.2 % vs. 0 %, p = 0.47), and cardio-metabolic health parameters, were similar between women with/without previous GDM. These results were supported by similar perinatal outcomes and child health at follow-up. The overall prevalence of prediabetes/T2D was high, but no differences in other cardio-metabolic risk markers were observed in women with prediabetes/T2D compared to women with normal glucose tolerance.

Conclusions
Despite high prevalence of GDM among Tanzanian women, the diagnosis was not associated with adverse pregnancy outcomes, nor with increased risk of prediabetes or T2D at follow-up. FPG and HbA1c may be poor markers for diabetes in this population, and further follow-up studies with longer time intervals are warranted to evaluate which GDM diagnostic criteria are most optimal for women in rural Tanzania and similar LMIC settings.