Objective: It is generally accepted that glucose tolerance deteriorates during pregnancy in the developed world. Several small studies have suggested that this may not be the case in sub-Saharan Africa. This study was designed to investigate changes in glucose tolerance in nondiabetic African women during pregnancy in Dar es Salaam, Tanzania.
Research design and methods: Women (n = 89) seen before the 14th wk of pregnancy without known diabetes were recruited: 58 had a 75-g OGTT in the 1st, 2nd, and 3rd trimesters and postpartum.
Results: Mean FBG levels were 3.9, 3.5, 3.6, and 3.7 mM in the 1st, 2nd, and 3rd trimesters and postpartum period, respectively. Values were significantly lower in the 2nd and 3rd trimesters than in the 1st and 2nd trimesters compared with postpartum. Mean 2-h blood glucoses were 4.7, 4.4, 4.3, and 4.2 mM, respectively. The 1st trimester value was significantly higher than in the 3rd trimester and postpartum. Fifteen (26%) of the 58 women showed a decreased or unchanged 2-h blood glucose during the course of pregnancy, 5 (9%) showed an increase, and no clear pattern was seen in 38 (67%). Values for fasting glucose showed similar trends.
Conclusions: We conclude that women during pregnancy in an urban African setting show little change in glucose tolerance. This contrasts with women in both the developed world, where glucose tolerance worsens, and in a rural African environment, where glucose tends to improve.