Establishing novel diagnostic criteria for the glucose tolerance test for the diagnosis of gestational diabetes and gestational hyperglycemia.

OBJECTIVE: To establish diagnostic criteria for the 75-g 2-h glucose tolerance test (GTT) to diagnose gestational diabetes and define the clinical entity of gestational hyperglycemia. METHODS: A retrospective analysis was performed of the results from 500 patients who had a 75-g 1-h glucose challenge test (GCT) in early pregnancy as part of a two-step approach to screening and testing for gestational diabetes. The selected cohort was considered to have normal islet ß-cell function, and upper glycemic levels of normal glucose tolerance in the third trimester were statistically calculated, taking the cutoff threshold values to be the diagnostic criteria for the 75-g 2-h GTT. Gestational hyperglycemia was diagnosed from the false-positive GCT result when ≥8.0 mmol/L (144 mg/dL). RESULTS: The diagnostic criteria for the 75-g 2-h GTT were calculated as follows: fasting plasma glucose ≥5.4 mmol/L (97 mg/dL); 1-h plasma glucose ≥10.5 mmol/L (189 mg/dL); and 2-h plasma glucose ≥8.4 mmol/L (151 mg/dL). The new criteria confirmed a prevalence of gestational diabetes of 11.1% and gestational hyperglycemia of 13.6% in the study population. CONCLUSION: Novel diagnostic criteria for the 75-g 2-h GTT were established by statistical analysis. This resulted in a more acceptable prevalence of gestational diabetes in our community and the false-positive GCT allowed the detection of gestational hyperglycemia.

Screening for gestational diabetes mellitus and hyperglycemia in pregnancy with the glucose challenge test administered in early pregnancy.

OBJECTIVE: To determine the cut-off value for the 75-g glucose challenge test administered in early pregnancy to screen for gestational diabetes mellitus and abnormal carbohydrate metabolism in pregnancy. METHODS: A prospective study involving 1500 antenatal patients attending a community hospital. Patients were screened with the 75-g 1-h glucose challenge test in early pregnancy and subsequently tested with the 75-g 2-h glucose tolerance test to diagnose gestational diabetes mellitus. Statistical methods were employed to determine the optimal plasma glucose cut-off value for a positive result in early pregnancy. RESULTS: A glucose challenge test value of 6.0 mmol/L (108 mg/dl) or more was selected as the preferred cut-off level for further testing with a sensitivity of 83.5% (95% confidence interval [CI] 77.0%-88.9%) and specificity of 49.2% (95% CI 46.5%-52.0%). CONCLUSION: An early pregnancy glucose challenge test reading of 6.0 mmol/L (108 mg/dl) or more is effective in screening for gestational diabetes mellitus; a value of 10.0 mmol/L (180 mg/dl) or more is effective for finding pre-pregnancy abnormalities of carbohydrate metabolism. The false-positive glucose challenge test diagnoses gestational hyperglycemia, the treatment of which will improve perinatal outcome. Further testing based on risk factors will exclude a false-negative glucose challenge test. A combination of universal early pregnancy screening and selective risk-factor testing is recommended to detect the full range of abnormalities of carbohydrate metabolism encountered in pregnancy.

ADIPS 2020 guideline for pre-existing diabetes and pregnancy.

This is the full version of the Australasian Diabetes in Pregnancy Society (ADIPS) 2020 guideline for pre-existing diabetes and pregnancy. The guideline encompasses the management of women with pre-existing type 1 diabetes and type 2 diabetes in relation to pregnancy, including preconception, antepartum, intrapartum and postpartum care. The management of women with monogenic diabetes or cystic fibrosis-related diabetes in relation to pregnancy is also discussed.

The ADIPS pilot National Diabetes in Pregnancy Audit Project.

BACKGROUND: Limited resources are available to compare outcomes of pregnancies complicated by diabetes across different centres. AIMS: To compare the use of paper, stand alone and networked electronic processes for a sustainable, systematic international audit of diabetes in pregnancy care. METHODS: Development of diabetes in pregnancy minimum dataset using nominal group technique, email user survey of difficulties with audit tools and collation of audit data from nine pilot sites across Australia and New Zealand. RESULTS: Seventy-nine defined data items were collected: 33 were for all women, nine for those with gestational diabetes (GDM) and 37 for women with pregestational diabetes. After the pilot, four new fields were requested and 18 fields had queries regarding utility or definition. A range of obstacles hampered the implementation of the audit including Medical Records Committee processes, other medical/non-medical staff not initially involved, temporary staff, multiple clinical records used by different parts of the health service, difficulty obtaining the postnatal test results and time constraints. Implementation of electronic audits in both the networked and the stand-alone settings had additional problems relating to the need to nest within pre-existing systems. Among the 496 women (45 type 1; 43 type 2; 399 GDM) across the nine centres, there were substantial differences in key quality and outcome indicators between sites. CONCLUSIONS: We conclude that an international, multicentre audit and benchmarking program is feasible and sustainable, but can be hampered by pre-existing processes, particularly in the initial introduction of electronic methods.

Gestational diabetes mellitus: clinical predictors and long-term risk of developing type 2 diabetes: a retrospective cohort study using survival analysis.

OBJECTIVE: We sought to determine the long-term risk of type 2 diabetes following a pregnancy complicated by gestational diabetes mellitus (GDM) and assess what maternal antepartum, postpartum, and neonatal factors are predictive of later development of type 2 diabetes. RESEARCH DESIGN AND METHODS: This was a retrospective cohort study using survival analysis on 5,470 GDM patients and 783 control subjects who presented for postnatal follow-up at the Mercy Hospital for Women between 1971 and 2003. RESULTS: Risk of developing diabetes increased with time of follow-up for both groups and was 9.6 times greater for patients with GDM. The cumulative risk of developing type 2 diabetes for the GDM patients was 25.8% at 15 years postdiagnosis. Predictive factors for the development of type 2 diabetes were use of insulin (hazard ratio 3.5), Asian origin compared with Caucasian (2.1), and 1-h blood glucose (1.3 for every 1 mmol increase above 10.1 mmol). BMI was associated with an increased risk of developing type 2 diabetes but did not meet the assumption of proportional hazards required for valid inference when using Cox proportional hazards. CONCLUSIONS: While specific predictive factors for the later development of type 2 diabetes can be identified in the index pregnancy, women with a history of GDM, as a group, are worthy of long-term follow-up to ameliorate their excess cardiovascular risk.

The Australasian Diabetes in Pregnancy Society consensus guidelines for the management of type 1 and type 2 diabetes in relation to pregnancy.

Strict control of blood glucose levels should be pursued before conception and maintained throughout the pregnancy (glycohaemoglobin [HbA(1c)] level as close as possible to the reference range). Before conception: high-dose (5 mg daily) folate supplementation should be commenced; oral hypoglycaemic agents should be ceased; and diabetes complications screening should take place. Management should be by a multidisciplinary team experienced in the management of diabetes in pregnancy. Blood glucose monitoring is mandatory during pregnancy, and targets are: fasting 4.0-5.5 mmol/L; postprandial < 8.0 mmol/L at 1 hour; < 7 mmol/L at 2 hours. A first trimester nuchal translucency (possibly with first trimester biochemical screening with pregnancy-associated plasma protein A and beta-human chorionic gonadotropin) should be offered. Ultrasound should be performed for fetal morphology at 18-20 weeks, if required, for cardiac views at 24 weeks and for fetal growth at 28-30 and 34-36 weeks. Induction of labour or operative delivery should be based on obstetric and/or fetal indications. Level 3 neonatal nursing facilities may be required and should be anticipated when birth occurs before 36 weeks, or if there has been poor glycaemic control. Insulin requirements fall rapidly during labour and in the puerperium. At this time, close monitoring and adjustment of insulin therapy is necessary.

Gestational diabetes in Victoria in 1996: incidence, risk factors and outcomes.

OBJECTIVES: To describe the epidemiology of gestational diabetes mellitus (GDM) in Victoria. STUDY DESIGN: Population study of all women having singleton births in Victoria in 1996. METHODS: Probabilistic record linkage of routinely collected data and capture-recapture techniques to provide an estimate of the incidence of GDM. MAIN OUTCOME MEASURES: Risk factors for and the adverse outcomes associated with GDM compared with the non-diabetic population by univariate and multivariate analysis. RESULTS: The estimated incidence of GDM was 3.6% (95% confidence interval [CI], 3.60%-3.64%). GDM is associated with women who are older, Aboriginal, non-Australian born, or who give birth in a larger hospital. The adverse outcomes associated with GDM pregnancies were hypertension/pre-eclampsia (adjusted odds ratio [OR], 1.6; 95% CI, 1.4-1.9), hyaline membrane disease (1.6; 1.2-2.2), neonatal jaundice (1.4; 1.2-1.7) and macrosomia (2.0; 1.8-2.3). Interventions during childbirth were also associated with GDM - for example, induction of labour (3.0; 2.7-3.4) and caesarean section (1.7; 1.6-1.9). CONCLUSION: Women with GDM had increased rates of hypertension, pre-eclampsia, induced labour, and interventional delivery. Their offspring had a higher risk of macrosomia, neonatal jaundice and hyaline membrane disease.