Diabetes screening in pregnancy failing women in rural Western Australia: An audit of oral glucose tolerance test completion rates.

OBJECTIVE: To quantify screening rate for gestational diabetes mellitus and completion of oral glucose tolerance test in rural and remote Western Australia. DESIGN AND PARTICIPANTS: Retrospective audit of 551 antenatal records from women of 16 years and older without pre-existing diabetes and with singleton pregnancies delivered in 2013. MAIN OUTCOME MEASURES: Number of women recorded screened for gestational diabetes mellitus in second or third trimester using oral glucose tolerance test or other tests; gestational diabetes mellitus rate. RESULTS: Only 278 (50.5%) women were screened with oral glucose tolerance test; 113 (20.5%) had no record of any screening related to gestational diabetes mellitus. In a nested mixed-effects logistic regression model, women with a previous gestational diabetes mellitus diagnosis, two or more risk factors (excluding ethnicity) or high-risk gestational diabetes mellitus ethnicity other than Australian Aboriginal were more likely to be screened, while Australian Aboriginal women were less likely to be screened with oral glucose tolerance test. Clinicians reported patient and clinician factors and logistical difficulties as reasons for the oral glucose tolerance test not being completed at their site. Of those screened with oral glucose tolerance test, a high rate of gestational diabetes mellitus was diagnosed (14.7% versus Western Australia state-wide average of 7.4%). CONCLUSION: Adherence to oral glucose tolerance test screening in rural Western Australia is inadequate for effective screening for gestational diabetes mellitus. Screening was not acceptable or available for a significant proportion of women at risk. Efforts to improve oral glucose tolerance test adherence and exploration of alternative gestational diabetes mellitus screening strategies are required.

Real-world screening for diabetes in early pregnancy: Improved screening uptake using universal glycated haemoglobin.

AIMS: To improve perinatal outcomes, screening for hyperglycaemia using 75 g oral glucose tolerance test (OGTT) is recommended for all pregnant women at 24-28 weeks gestation (routine), and earlier if high-risk. Screening coverage for remote and Aboriginal Australian women is less than ideal. This study examined OGTT completion (early and routine) by women from rural and remote Western Australia compared with early glycated haemoglobin (HbA1c). METHODS: In 2015-2018, 27 primary health care sites recruited 600 (233 Aboriginal) women aged ≥16-years, without pre-existing diabetes, who delivered >30-weeks gestation. All women presenting <20-weeks gestation (541) were offered an early study HbA1c. Early OGTTs were requested at the discretion of the local clinician, with routine OGTT offered at 24-28 weeks. RESULTS: HbA1c uptake was high (85.7% Aboriginal, 86.4% non-Aboriginal); OGTT completion in Aboriginal women was low (early OGTT: 38.6% v 69.6% non-Aboriginal, P < 0.001; routine OGTT: 44.5% v 84.7% non-Aboriginal, P < 0.001). Aboriginal women with both early tests had HbA1c completed 3-weeks prior to OGTT (9.6 ± 3.5 v 12.5 ± 3.5 weeks gestation, P < 0.001). CONCLUSIONS: Universal early pregnancy HbA1c appears feasible as an early screening test for women at risk of hyperglycaemia in pregnancy and would expedite and increase screening in Aboriginal women compared to an early OGTT.

Prediabetes and pregnancy: Early pregnancy HbA1c identifies Australian Aboriginal women with high-risk of gestational diabetes mellitus and adverse perinatal outcomes.

AIMS: To assess whether early pregnancy HbA1c can predict gestational diabetes mellitus (GDM) and adverse birth outcomes in Australian women. METHODS: Prospective study of 466 women without diabetes, aged ≥16-years at first antenatal presentation. Recruitment was from 27 primary healthcare sites in rural and remote Australia from 9-January 2015 to 31-May 2018. HbA1c was measured with first antenatal investigations (<20-weeks gestation). Primary outcome measure was predictive value of HbA1c for GDM, by routine 75 g oral glucose tolerance test (OGTT; ≥24-weeks gestation), and for large-for-gestational-age (LGA) newborn. RESULTS: Of 396 (129 Aboriginal) women with routine OGTT, 28.8% had GDM (24.0% Aboriginal). HbA1c ≥5.6% (≥38 mmol/mol) was highly predictive (71.4%, 95% CI; 47.8-88.7%) for GDM in Aboriginal women, and in the total cohort increased risk for LGA newborn (RR 2.04, 95% CI; 1.03-4.01, P = 0.040). There were clear differences between Aboriginal and non-Aboriginal women: 16.3% v 5.2% (P < 0.001) had elevated HbA1c whereas 12.4% v 29.6% (P < 0.001) developed hyperglycemia during pregnancy. CONCLUSIONS: Early pregnancy HbA1c ≥5.6% (≥38 mmol/mol) identifies Aboriginal women with apparent prediabetes and elevated risk of having an LGA newborn. Universal HbA1c at first antenatal presentation could facilitate earlier management of hyperglycemia and improved perinatal outcome in this high-risk population.