Efficiency of gestational diabetes mellitus screening and socio-demographics of pregnant subjects attending antenatal care.

Abstract Background: Gestational diabetes mellitus (GDM) is a glucose intolerance of variable severity that can have devastating effect on the fetus.1 Aim: To determine the efficiency of GDM screening and the sociodemograhic variables of mothers among population at risk.Methods: A cross-sectional study among pregnant women booked for antenatal care (ANC) at Federal Medical Centre Abeokuta, Nigeria. A multistage sampling technique was used to select 100 pregnant women attending ANC. The subjects were screened with World Health Organization (WHO) diagnostic criteria2 for gestational diabetes mellitus using 75g Oral Glucose Tolerance Test (OGTT) with either fasting plasma glucose ≥ 5.1 mmol, or the 2 hour post glucose load ≥ 8.5 mmol or both. To determine if gestational diabetes is present in pregnant women, a standard OGTT was performed after overnight fasting (8–12 hours) by giving 75 g anhydrous glucose in 250–300 ml. The pregnant subjects that met the inclusion criteria were scheduled to have overnight fasting of between 8 to 12hours before fasting plasma glucose (FPG) testing, having done random plasma glucose (RPG) test at first presentation. Samples of venous blood were collected into sodium fluoride container. The glucose oxidase method of estimation of plasma glucose was used to assay the samples3. It involved the use of the enzyme glucose oxidase that reacts with glucose, water and oxygen to form gluconic acid and hydrogen peroxide. The hydrogen peroxide produced oxidizes a chromogen (or the consumption of oxygen) which is measured to estimate the amount of glucose present.Results: During this study, a total of 100 eligible pregnant women were screened for GDM using FPG, RPG and the 75-OGTT. The mean age ± standard deviation (sd) of the participants was 34.81±4.04 yrs; mean BMI was 31.46±7.29 kg/m2 and modal parity was 1 (32%) (Table I). The majority of the pregnant subjects, 74 (74%) had tertiary level of education.The RPG cut off values of ≥7.8 mmol/l gave PPV of 66% and NPV of 72.3% with PLR and NLR of 4.76 and 0.89 respectively. The efficiency of RPG ≥7.8 mmol/l in diagnosing GDM was 72%. Also increasing the cut-off point of RPG to ≥11.1 mmol/l gave efficiency of 72% while the highest efficiency was achieved using FPG of ≥5.1 mmol/l which gave the efficiency of 95%. The greatest positive predictive value of 100% was given by FPG value ≥7.0 mmol/l and RPG value of ≥11.1 mmol/l.Conclusion: GDM screening with FPG revealed high efficiency of 95% at threshold of 5.1 mmol/l. Maternal age of 35-40 yrs had the highest incidence of GDM in our population.