Predictive Value of Fasting Plasma Glucose on First Antenatal Visit before 20 Weeks of Gestation to Diagnose Gestational Diabetes Mellitus
Dr. Manisha Sharma,
26, SFS DDA Flats, Mukherji Nagar, Delhi-110009, India.
Introduction: Gestational Diabetes Mellitus (GDM) is an important public health concern due to its association with adverse foetomaternal outcome. Steadily increasing prevalence necessitates screening and early treatment of women at risk of developing the disease in order to reduce threats to maternal and foetal health.
Aim: To find out Fasting Plasma Glucose (FPG) in the pregnant women at first antenatal visit and to correlate it with Oral Glucose Tolerance Test (OGTT) with 75 gm glucose at 24-28 weeks of gestation.
Materials and Methods: It was a hospital based prospective study conducted on 246 antenatal patients (<20 weeks gestation) in the Department of Obstetrics and Gynaecology at Hindu Rao Hospital, Delhi, India. The patients were subjected to FPG test on first antenatal visit and patients with FPG < 126 mg/dL were again subjected to OGTT with 75 gm glucose at 24 to 28 weeks. All the analysis were carried out on SPSS software version 16.0 (Chicago, Inc., USA). Cutoff levels of fasting glucose were analysed as screening test in correlation with OGTT.
Results: The incidence of GDM was 6.5% in our study. Mean gestational age on first visit was 16.48Â±1.77 weeks. The mean age in GDM and Normal Glucose Tolerance (NGT) group was 24.56Â±2.87 and 25.11Â±4.11 year respectively (p=0.01). Mean Body Mass Index (BMI) was 22.97Â±2.68 and 23.25Â±2.59 kg/m2 in the GDM and NGT group respectively (p-value 0.68). As the pregnancy advanced, 18.75% and 5.2% cases developed preeclampsia in the GDM and NGT group respectively (p-value<0.01). Glycosuria was observed in 31.2% in GDM group and none in the NGT group. FPG was found to be significantly (p=0.0001) higher in GDM (99.44Â±10.26) than NGT (76.26Â±10.35). OGTT at 0, one and two hours was significantly (p=0.0001) higher in GDM group. There was a strong positive correlation between FPG and GTT at 0, one and two hour respectively. Receiver Operating Characteristic (ROC) curve showed that a cut off level of fasting blood glucose =84.5 mg/dL had a sensitivity of 93.8% and specificity of 74.3%. The positive and negative predictive values were 20.3% and 99.4% respectively.
Conclusion: FPG on first antenatal visit is a useful screening test to identify GDM on first antenatal visit. Early diagnosis of the disease and early intervention will always improve the pregnancy outcome.