| Methods |
Multi centre trial: 18 centres in Australia and UK.
Randomisation method: performed centrally with the use of numbers generated by computer with variable block sizes of 6, 8, and 10.
Blinding of intervention and outcome assessment: women that were assigned to the intervention group received a slip indicating a diagnosis of glucose intolerance and the plan for intervention, women assigned to routine care received a slip indicating they did not have GD. The full numerical results of the oral glucose‐tolerance test were not released to the women or their providers until after birth, before discharge from hospital.
Dropouts: no losses to follow up for primary and secondary clinical outcomes for women. No losses to follow up for primary and secondary outcomes for infants.
Intention‐to‐treat analysis was used. |
| Participants |
1000 women.
Inclusion criteria: impaired glucose tolerance (defined as having one or more risk factors for GD on selective screening or a positive 50 g oral glucose challenge test (glucose level 1 hour after glucose challenge at least 7.8 mmol per litre [140 mg per decilitre])), and had a 75 g OGTT at 24 to 34 weeks' gestation in which the venous plasma glucose level was less than 7.8 mmol per litre after an overnight fast and was 7.8 to 11.0 mmol per litre (198 mg per decilitre) at 2 hours).
Exclusions: women with previously treated GD or active chronic systemic disease (except essential hypertension), more severe impairment or less than 16 or more than 30 weeks' pregnant.
Setting: antenatal clinic. |
| Interventions |
Intervention group: care replicated clinical care in which universal screening and treatment for GD was available, individualised dietary advice from a qualified dietician, instructions on how to self‐monitor glucose levels 4 times a day until fasting glucose levels of at least 3.5 mmol per litre [63 mg per decilitre] and no more than 5.5 mmol per litre [99 mg per decilitre], preprandial levels of no more than 5.5 mmol per litre, and levels 2 hours postprandially that were no more than 7.0 mmol per litre [126 mg per decilitre], followed by daily monitoring at rotating times during the day; and insulin therapy, with the dose adjusted based on glucose levels, if there were 2 capillary‐blood glucose results during the 2‐week period in which the fasting level was at least 5.5 mmol per litre or the postprandial level was at least 7.0 mmol per litre at 35 weeks' gestation or less, if the postprandial level was at least 8.0 mmol per litre (144 mg per decilitre) at more than 35 weeks' gestation, or if one capillary‐blood glucose results during the 2‐week period was at least 9.0 mmol per litre (162 mg per decilitre).
Control group: care replicated clinical care in which screening for GD was not available, women and caregivers were not aware of the diagnosis of glucose intolerance, at the discretion of the attending clinician, if indications arose that were suggestive of diabetes, further assessment for GD was permitted, with treatment as considered appropriate. |
| Outcomes |
Primary outcomes ‐ infant: composite measures of serious perinatal complications (defined as 1 or more of death, shoulder dystocia, bone fracture, and nerve palsy), admission to neonatal nursery, and jaundice requiring phototherapy.
Primary outcomes ‐ women: need for IOL and caesarean section, health status, and psychological outcomes.
Secondary outcomes ‐ infant: gestational age at birth, birthweight, Apgar score of less than 7 at 5 minutes, hypoglycaemia requiring IV therapy, convulsions, RDS.
Secondary outcomes ‐ women: number of prenatal visits to a health professional, mode of birth, weight during pregnancy, number of antenatal admissions, presence or absence of PIH, perineal trauma, PPH, breastfeeding at hospital discharge. |
| Notes |
93% of the women had been found to be at risk of GD on the basis of OGTT, and the remainder on the basis of risk factors.
5 perinatal deaths (3 stillbirths and 2 neonatal deaths) occurred in the control group: 2 stillbirths were unexplained intrauterine deaths at term of appropriately grown infants, and 1 at 35 weeks' gestation, was associated with pre‐eclampsia and intrauterine growth restriction. 1 infant had a lethal congenital anomaly, and 1 infant died after an asphyxial condition during labour with antepartum haemorrhage.
After consent had been obtained, a proportion of the women (not fewer than 1 in 5) who had normal oral GTT results were assigned to the routine‐care group to help maintain blinding. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Low risk |
A ‐ Adequate |
