Background:  Obesity is common in pregnancy and results in morbidity to mother and newborn.

Aim:  To evaluate whether a four‐step multidisciplinary protocol of antenatal care for overweight and obese women would reduce the incidence of gestational diabetes.

Methods:  Pregnant women were approached at their first antenatal visit, and body mass index (BMI) was calculated to determine whether they were overweight or obese (BMI > 25). Eligible women were randomised to standard obstetric antenatal care or four‐step multidisciplinary antenatal care. Clinic protocol included (i) continuity of obstetric provider; (ii) weighing on arrival at each visit; (iii) a five brief minute intervention by a food technologist who asked about the women’s eating habits of the previous day, provided information on reading food labels, shopping lists of affordable foods available from local shops and recipes for a healthy pregnancy diet; and (iv) clinical psychology management to assess symptoms of depression and anxiety, stressful life events and determine whether psychological factors were involved in eating patterns. Labour and delivery data were audited from the medical records to determine the final incidence of gestational diabetes. The primary outcomes were gestational diabetes and weight gain.

Results:  The intervention was associated with a significant reduction in the incidence of gestational diabetes (6 versus 29%, OR 0.17 95% CI 0.03–0.95, P = 0.04). It was also associated with reduced weight gain in pregnancy (7.0 versus 13.8 kg, P < 0.0001). Despite this, birthweight of newborns was similar [3.5 (0.1) kg versus 3.4 (0.1) kg P = 0.16].

Conclusion:  A four‐step management plan adopted with obese women reduces the incidence of gestational diabetes.