Maternal ante-natal parameters as predictors of persistent postnatal glucose intolerance: a comparative study between Afro-Caribbeans, Asians and Caucasians

AIMS: To measure the prevalence of persistent glucose intolerance at 6-12 weeks postpartum in various ethnic groups to assess the value of targeted postpartum screening. METHODS: A retrospective study was performed using computerized databases from two large maternity units within one UK region. Both units used the same screening strategy for gestational diabetes mellitus (GDM) and the same postpartum follow-up at 6-12 weeks using a 75-g oral glucose tolerance test (OGTT). A total of 221 women with a diagnosis of GDM/impaired glucose tolerance (IGT) in the index pregnancy in addition to a completed postpartum 75-g OGTT were studied. Of these, 91 were Caucasian, 89 were of Indo-Asian (Asian) origin and 41 were of Afro-Caribbean origin. RESULTS: The study showed that 35% Indo-Asians had persistent postpartum glucose intolerance compared with 7% Caucasians and 5% Afro-Caribbeans (P <0.003). Insulin requirement during pregnancy and a diagnosis of gestational diabetes prior to 20 weeks of pregnancy were predictive for persistent postpartum glucose intolerance amongst Indo-Asians. CONCLUSIONS: The frequency of postpartum glucose intolerance among Indo-Asian women is significantly greater than among age-matched Caucasian and Afro-Caribbean women. We suggest that all Indo-Asian women with gestational diabetes should undergo postpartum screening for persistent glucose intolerance. However, in non-Asian women selective screening may be more cost effective.