Ferrara 2011.

Methods	Pilot RCT, 2 arms with individual randomisation.
Participants	Setting: 197 women receiving care through Kaiser Permanente Medical Care Program in Northern California USA. The study was carried out between 2005‐2008. Inclusion criteria; 96 women diagnosed with GDM. Exclusion criteria:  aged under 18 years, multiple gestation, diabetic retinopathy, high‐risk pregnancy (drug or alcohol abuse, chronic illness, thyroid disease or pregnancy complications), non‐English speaker.
Interventions	Intervention group (96 women) a complex lifestyle intervention including telephone support encouraging changes in diet and exercise and promoting breastfeeding.  During pregnancy women had individual counselling from a dietician and this was followed by 2 telephone counselling contacts to encourage women to comply with IOM guidelines on weight gain and to engage in moderate intensity exercise. Women also received written information on diet. Towards the end of pregnancy women were referred to a lactation consultant who then scheduled between 1‐4 telephone calls during the first 6 weeks after delivery to encourage breastfeeding. During the postpartum period women had 8‐16 sessions on diet and exercise, 2 face‐to‐face with dieticians the rest over the telephone which encouraged women to exercise and reduce fat intake so as to regain their pre‐pregnancy weight or reduce weight if they were overweight. Women were given diaries to monitor their exercise. Usual care: 101 women received printed educational materials on GDM.
Outcomes	Breastfeeding at 6 weeks and 7 months postpartum, reported amount of calories from fat and change in physical activity, number of women exceeding IOM weight gain goals at 6 weeks and 7 and 12 months postpartum.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A computer randomisation program.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not mentioned.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	It was stated that research assistants collecting outcome data were unaware of group assignment. It was not clear if attempted blinding was successful.
Incomplete outcome data (attrition bias) All outcomes	High risk	In the intervention group 20% were lost to follow‐up by 12 months postpartum compared with 10% in the control group. It was not clear why loss was greater in the intervention group.
Selective reporting (reporting bias)	Unclear risk	Assessed from published study report.
Other bias	Unclear risk	Results were not consistent over time so some results were difficult to interpret. Groups appeared balanced at baseline.