Reference values for glucose tolerance test in the urban Zimbabwean pregnant woman

A 50 g oral glucose tolerance test (OGTT) was performed on normal pregnant urban Zimbabwean women at 26-28 weeks (n = 65) and 36-40 weeks (n = 72) gestation. Women with factors predisposing to impaired glucose tolerance were excluded. The fasting, one hour and two hours values were compared to the North American standards as proposed by O'Sullivan and Mahan which are currently in use. The mean fasting levels were significantly higher and those at one and two hours significantly lower than the standards. The study also failed to demonstrate impairment of glucose tolerance with advancing gestation. These may have implications in the screening for impaired glucose tolerance in our African population.