Prospective evaluation of pregnancy outcomes in women with pre-gestational diabetes over 6 years. The ATLANTIC Diabetes in Pregnancy group represents 5 antenatal centres along the Irish Atlantic seaboard, providing care for women with diabetes throughout pregnancy. In 2007 the group published a report that recognised that women were poorly prepared for pregnancy and that outcomes were sub-optimal. A change in practice occurred, offering women specialist-led, evidence-based care, both pre-pregnancy and combined antenatal/diabetes clinics during pregnancy. We now compare outcomes from 2005-2007 with 2008-2010. There was an increase in the numbers attending pre-conception care. Glycemic control before and throughout pregnancy improved. There was an overall increase in live births and decrease in perinata mortality rate. There was a decrease in large-for-gestational-age babies in mothers with Type 1 Diabetes. Elective Caesarean section rates increased while emergency section rates decreased. More women had Type 2 diabetes over time and these women were more likely to be obese. Changing the process of clinical care delivery can improve outcomes in for women with pre-gestational diabetes.