Background: Glucose tolerance testing in pregnancy identifies many women with glycaemic responses that exceed normal range but that do not meet the threshold required to diagnose Gestational Diabetes Mellitus. It is controversial whether maternal hyperglycemia less severe than in diabetes is associated with increased risk of adverse pregnancy outcome or not. Materials and methods: All women were subjected to Glucose Challenge Test(GCT) with 50 gram glucose either at first visit or between 24-28 weeks on the basis of risk profile. High risk cases were screened at first visit and the rest between 24-28 weeks. Patients with a GCT value ≥200mg/dl were not subjected for GTT and were diagnosed as GDM.Value of GCT <140 mg/dl was taken as normal. Irrespective of GCT result, women were subjected to Oral Glucose Tolerance Test (OGTT) as recommended by WHO with 75 gram glucose using WHO criteria. Study group was identified with 4 categories with abnormal glucose homoeostasis as defined by the following criteria:
1. Abnormal GCT (>140 mg/dl) with normal OGTT;
2. Normal GCT with only Impaired Fasting Glucose(IFG) in OGTT;
3. Normal GCT with Gestational Glucose Intolerance(GGI);
4. Patients diagnosed as GDM:
a. If fasting is >126mg/dl;
b. If 2hr OGTT ≥ 140mg/dl & ≤ 199 mg/dl;
c. If value of either GCT or OGTT >200 mg/dl.
The control group comprised of women with normal GCT and normal OGTT. In all the above groups, adverse prenatal outcome and maternal outcomes were evaluated by the primary and secondary outcome measures.
Results: There were 10 cases (15.3%) of hypertensive disorder of pregnancy in the study group (3 cases of gestational hypertension in abnormal GCT, 3 cases of pre eclampsia in each GGI and GDM and 1 antepartum eclampsia in GGI category) and 2 cases in control group (3%) (p=0.03). There were 2 cases of Fetal Growth Reduction (FGR) and 5 cases of Premature Rupture Of Membranes(PROM) in both study and control group. There was 1 case of cholestasis of pregnancy in study group. Term inductions were 11 and 13 in the study and control group respectively.Within the study group number of cases induced were more in GGI(n=7) and GDM(n=4) category. There were 14 caesarean sections (21.5%) and 2 (3%) instrumental deliveries among the study group. However there were 6 caesarean sections (9.2%) and no instrumental deliveries among control groups .The rate of elective LSCS is more in GDM (n=5) vs other 3 categories and the difference is significant (p=0.04) The overall number of LSCS (14 cases) was significantly higher in GDM.
Conclusion: Cases with abnormal glucose homeostasis of lesser degree than GDM, like only abnormal GCT, IFG and GGI also were observed to have adverse maternal outcomes than controls, in form of hypertensive disorders of pregnancy, significantly higher LSCS rates, and increased risk of macrosomia. Instead of 2 step procedure, single step screening cum diagnostic test with 75 gm OGTT for diagnosing GDM could be an option to be universally practiced.