5.0.0.0 Preexisting T1D & T2D Mgmt.
5.1.0.0 Insulin Use
Recommendation
14.11 Insulin is the preferred agent for management of both type 1 diabetes and type 2 diabetes in pregnancy because it does not cross the placenta and because oral agents are generally insufficient to overcome the insulin resistance in type 2 diabetes and are ineffective in type 1 diabetes. E
The physiology of pregnancy necessitates frequent titration of insulin to match changing requirements and underscores the importance of daily and frequent self-monitoring of blood glucose. Early in the first trimester, there is an increase in insulin requirements, followed by a decrease in weeks 9 through 16 (60). Women, particularly those with type 1 diabetes, may experience increased hypoglycemia. After 16 weeks, rapidly increasing insulin resistance requires weekly increases in insulin dose of about 5% per week to achieve glycemic targets. There is roughly a doubling of insulin requirements by the late third trimester. In general, a smaller proportion of the total daily dose should be given as basal insulin (<50%) and a greater proportion (>50%) as prandial insulin. Late in the third trimester, there is often a leveling off or small decrease in insulin requirements. Due to the complexity of insulin management in pregnancy, referral to a specialized center offering team-based care (with team members including maternal-fetal medicine specialist, endocrinologist, or other provider experienced in managing pregnancy in women with preexisting diabetes, dietitian, nurse, and social worker, as needed) is recommended if this resource is available.
None of the currently available human insulin preparations have been demonstrated to cross the placenta (61-66).
A recent Cochrane systematic review was not able to recommend any specific insulin regimen over another for the treatment of diabetes in pregnancy (67).