Type 1 diabetes in pregnancy presents multiple challenges to healthcare groups. Although there are debates regarding the precise pathophysiology of the different complications of type 1 diabetes during pregnancy, there is increasing evidence that good periconception and early pregnancy glycaemic control will reduce the rate of all complications, including macrosomia. The provision of organized prepregnancy care for this group allows an opportunity to reinforce the need for tight glycaemic control, to commence vitamin supplementation, to identify those with complications of diabetes who require more specialist evaluation and preparation, and to inform women of pregnancy risks. How this type of detailed care is provided is a major organizational issue for all healthcare systems. Optimal outcome during pregnancy is achieved by intense management by both obstetric and diabetic services. Many interventions and strategies during pregnancy, including the degree of glycaemic control, have a poor evidence base. The demands on pregnant women with type 1 diabetes should not be underestimated.