Prevalence of gestational diabetes mellitus in South India (Tamil Nadu)--a community based study.

AIM: Women diagnosed to have Gestational Diabetes Mellitus (GDM) are at increased risk of developing diabetes in future. Thus, diagnosis of GDM is an important public health issue. In a random survey 16.2% of pregnant women were found to have GDM in the Chennai urban population. Hence we undertook a planned community based study to ascertain the prevalence of GDM. MATERIALS AND METHODS: We conducted a prospective screening for GDM in the urban, semi urban and rural areas. All pregnant women irrespective of gestational weeks underwent a 75 g glucose challenge test in the fasting state. Diagnosis of GDM was made if the 2 hr plasma glucose was > or = 140 mg/dl (WHO criteria). RESULTS: A total of 4151, 3960 and 3945 pregnant women were screened in urban, semi urban and rural areas, respectively. GDM was detected in 739 (17.8%) women in urban, 548 (13.8%) in semi urban and 392 (9.9%) in rural areas. Out of 1679 GDM women, 1204 (72%) were detected in first visit and the remaining 28% in subsequent visits. A significant increase (P < 0.0001) in the prevalence of GDM was observed with family history of diabetes, increased maternal age and BMI. A trend for increased prevalence of GDM was observed in women with less physical activity, however, not statistically significant. CONCLUSION: In this community based study, the prevalence of GDM varied in the urban, semi urban and rural areas. Age > or = 25 years, BMI > or = 25 and family history of diabetes were found to be risk factors for GDM.

Glycemic level at the first visit and prediction of GDM.

OBJECTIVE: To evaluate the glycemic level at the first visit that is likely to predict gestational diabetes mellitus (GDM). METHODS: Consecutive pregnant women underwent a 75g oral glucose tolerance Test (OGTT) recommended by WHO and diagnosed GDM if 2hr post plasma glucose (PG) value > or = 140 mg/dl. Women with normal OGTT results at the first visit were screened again with an OGTT at the subsequent visits. RESULTS: A total of 4151 pregnant women from different trimesters underwent OGTT. Of them 739 women (17.8%) had GDM. Among the GDM women, 528 (71.4%) were detected at the first visit. On screening during subsequent visits, GDM was diagnosed in the remaining 211(28.6%) women who had normal OGTT in the first visit. We performed the analysis taking the glycemic level in the first visit of 211 pregnant women who manifested GDM in the subsequent visit. During normal pregnancy, 2hr PG level is < 120 mg/dl. Taking this value into consideration among the 211 women who turned to have GDM in the subsequent visits 119 women (56.4%) had 2hrPG > or = 120 mg/dl and the remaining 92(43.6%) had 2hrPG < 120 mg/dl. CONCLUSION: Pregnant women irrespective of 2 hr PG > or = or < 120 mg/dl at initial visit progressed to GDM in the subsequent visit. No glycemic level in the early weeks of pregnancy predicts GDM and at the same time at no statistically significant glycemic cut-off level could we say that a woman will not develop GDM. Hence rescreening in the subsequent trimester or visits is essential.