Aim Estimates of gestational diabetes mellitus (GDM) vary widely because of varying diagnostic criteria. Screening of pregnant women using modified (fasting+2 hour glucose only) International Association of Diabetes and Pregnancy Study Group criteria (IADPSG) has been available in Fiji since 2013. This study is the first hospital-based, analysis of the screening coverage and the resulting one-year prevalence. Prior prevalence (2009-2013) using the 1998 ADIPS criteria was relatively stable at ~1.4%.
Methods Women attended the antenatal clinic of the Colonial War Memorial Hospital (CWMH) in Suva (2013 -14) for 2 hr 75g oral glucose tolerance test (OGTT) or 50g Glucose Challenge Test≥7.8mmol/L and OGTT if at high/low risk of GDM. GDM diagnosed if fasting glucose ≥5.1 mmol/L and/or 2hr ≥8.5mmol/L unless diabetes in pregnancy (DIP) was present (fasting≥7.0 mmol/L and/or 2hr ≥11.1 mmol/L). Obesity was defined as BMI≥ 30kg/m2. Demography, risk factors (positive family history of diabetes, history of GDM, baby>4000g, still birth and neonatal death) and clinical data were extracted, retrospectively. The prevalence pre and post- IADPSG implementation and the categorical data were calculated.
Results Of the 8628 singleton births (women aged 38±2yrs), 301(3.4%) had diabetes: GDM/DIP/pre-exisiting DM 2.4%/0.5%/0.1%, respectively and 0.4% unretrieved records. The age-specific prevalence of GDM was 0.5%, 1.8%, 0.6% for 16-25, 26-35 and >35 years, respectively, 63% were obese, 66% had either any risk factor (51%) or 2/more risk factors (15%), mostly strong family history (51%). The mean gestational age at delivery was 38.5±2.1wks (GDM 38.6±2.0 vs DIP 37.7±2.3 p<0.05). Compared with non-diabetes, GDM women had significantly higher risks of caesarean section (OR=2.26; 95%CI:1.72/2.95), hypertensive disorder (OR=4.68; 3.34/6.47), stillbirth (OR=13.08; 7.65/21.7) but similar neonatal death risk. Higher birthweight for neonates with shoulder dystocia (4442g vs 3417g; p<0.001) with 20% of those with macrosomia (>4.0kg birthweight) developing shoulder dystocia.
Conclusion. Adopting the modified IADPSG criteria at the CWM hospital increased the prevalence of GDM (3.4%) and identified women at increased risk of adverse pregnancy outcomes in Fiji.
Key Words: International Association of Diabetes and Pregnancy Study Group’s criteria (IADPSG), Gestational Diabetes (GDM), Prevalence, Diabetes in Pregnancy, Macrosomia, Shoulder Dystocia.