Background: Glucose intolerance during pregnancy predisposes the offspring for increased risk of developing glucose intolerance in the future. This vicious cycle is likely to influence and perpetuate the incidence and prevalence of glucose intolerance in any population.
Aim: No data is available about the prevalence of glucose intolerance during pregnancy in our country and hence a study was undertaken on this aspect.
Methods: This study was performed in the antenatal clinic of Government Maternity Hospital, Chennai, India. As a pregnant woman in second or third trimester checks into the antenatal clinic, she was given 50 gm oral glucose load and blood sample was collected after one hour. This test was performed on 1251 pregnant women. They were requested to come after 72 hours for the 75 gm OGTT recommended by WHO. Among the 1251 women, 891 responded. The blood sample was taken in the fasting state and at 2 hours after 75 gm of oral glucose. Diagnosis was based on the WHO criteria for gestational diabetes mellitus (GDM).
Results: The mean age of these pregnant women was 23+/-4 years. There was a significant increase in the prevalence of GDM in relation to gravida. The effect of BMI did not quite reach statistical significance (chi2 (df=1) = 3.659, P = 0.055), but a model of linear trend was significant. Of the 1251 women who underwent the 50 gm oral glucose challenge test, 670 (53.55%) had one hour plasma glucose > or = 130 mg/dl. Among the 891 pregnant women who had 75 gms OGTT, 168 (18.9%) were diagnosed as GDM, taking both FPG > or = 126 mg/dl and/or 2 hr PPG > or = 140 mg/dl as cut-off values. Taking only 2 hr plasma glucose for analysis, 144 (16.2%) had a value > or = 140 mg/dl. A similar study was conducted in different parts of the country taking only the 2 hr 75 gm post-glucose value of > or = 140 mg/dl as diagnostic criteria for GDM. Of the total number of pregnant women (n = 3674) screened, 16.55% of them found to have GDM.
Conclusion: Our study has documented the increased prevalence of GDM in our population necessitating universal screening for glucose intolerance in pregnancy. Using 2 hr plasma glucose > or = 140 mg/dl as a one step procedure is simple and economical, particularly for the countries ethnically more prone to high prevalence of diabetes.