Study of impaired glucose tolerance by random plasma glucose measurement in the third trimester of pregnancy.

Thesis Report.

ABSTRACT: The hospital-based, prospective study was conducted among 670 pregnant women with 29-34 weeks of gestation attending the antenatal clinic of maternity hospital. The objectives of the study were (i) to find out the incidence of gestational glucose intolerance (GGI) by single random plasma glucose measurement and confirm the positive cases as true diabetic by glucose tolerance test (GTT), and (ii) to see the fetomaternal outcome of the gestational diabetic mothers. The data were collected three days a week. Total duration of study was 10 weeks. The women were screened for gestational glucose oxydase (Enzyme) method. Gestational glucose intolerance was diagnosed in women having either the plasma glucose value > 6.1 mmol/l (110 mg%) within 2 hours of meal or 5.6 mmol/1 (100 mg%) after 2 hours of meal. Women with gestational glucose intolerance were selected for glucose tolerance test with 75 gm oral glucose. Plasma glucose values of fasting and after 2 hours were interpreted according to following WHO criteria: 1. Diabetes mellitus (DM) is called if fasting venous plasma glucose value > 7.8 mmol/1 or 11.1 mmol/1 after 2 hours of glucose intake. 2. Impaired glucose tolerance (IGT) is called if glucose value between 7.8 -11.1 mmol/1 (140-200mg%) after 2 hours of glucose intake. The incidence of gestational glucose intolerance was found in 53 (8%) out of total cases. Out of 53, only 32 cases (21 failed to follow up)returned for GTT. Only one case (3.1%) was detected as having IGT and that accounts for 0.15% of total study cases. No case was identified as having diabetes mellitus (DM). Out of 315 cases analysed for the study of toleration of plasma glucose level with type of meal, number of GGI cases were found higher among those who had rice (17.64%) than those who had bread and tea (5.18%) before the test. The relation of plasma glucose level with the type of meal taken was significant (X = 10.96, p=0.0009) Those who had high fasting venous plasma glucose values also had high plasma glucose values after 2 hours. There was moderate degree of correlation between plasma glucose level during fasting and > 2 hours of oral glucose ingestion (r=0.513, p0.003). Observing the birth weight (wt) in relation to plasma glucose level, mean fetal birth wt, of babies born to women with random plasma glucose level < 60 mg% was < 2.5kg, 61-100 mg% was 2.75kg and 101-140 mg% was 3.25 kg. So there was a association between maternal plasma glucose level and birth wt, of babies, (X2 = 23.37, p = 0.00003). Large baby with birth weight >- 4 kg was found to be related to high body mass index (BMT) and all of those were male babies. There was no relationship between random maternal plasma glucose level and GGI to large baby >- 4 kg. In this study, with sample size mentioned above, GGI was found in 8 and IGT in 0.15%. Not a single diabetic case was detected, even in women who had risk factors for DM.

Eng.