Background There is now sufficient evidence to show that treating gestational diabetes improves outcomes for women and babies. Following the publication of NICE guidance and Metformin in Gestational diabetes trial (MiG), metformin alone or with supplemental insulin was introduced as a method of treatment for gestational diabetes at Liverpool Women's hospital in 2008.

Methods Retrospective review of outcomes of all pregnant patients diagnosed with gestational diabetes from 2008 to 2010 at Liverpool Women's Hospital.

Objectives The purpose of this review was to compare outcomes in pregnant women with gestational diabetes in routine clinical practice with those in a trial setting (MiG trial).

Results Outcomes in 158 women have been analysed to date. 111 patients received metformin for treatment. 41% of them needed supplemental insulin (46.3% MiG trial). In 8% of our women metformin was stopped due to side effects (1.9% MiG trial). Overall neonatal complication rate was 36% in the metformin group (32% MIG trial) and 37% in the insulin group (32% MiG trial). Preterm birth rate was 9% in the metformin group (12.1% MiG trial) and 6.2% in the insulin group (7.6% MiG trial).

Conclusion Full cohort data will be presented. We have found a similar rate of neonatal complications and preterm birth rates to the MiG trial. Our cohort has a higher rate of women in whom metformin was stopped due to side effects. This could reflect a different population group and a lower threshold to stop metformin.