Clinical Management of Women with Monogenic Diabetes During Pregnancy

Laura T. Dickens, Rochelle N. Naylor

Monogenic diabetes accounts for 1-2% of all diabetes cases, but is frequently misdiagnosed as type 1, type 2, or gestational diabetes. Accurate genetic diagnosis directs management, such as no pharmacologic treatment for GCK-MODY, low-dose sulfonylureas for HNF1A-MODY and HNF4A-MODY, and high-dose sulfonylureas for KATPchannel-related diabetes. While diabetes treatment is defined for the most common causes of monogenic diabetes, pregnancy poses a challenge to management. Here, we discuss the key issues in pregnancy affected by monogenic diabetes. General recommendations for pregnancy affected by GCK-MODY determine need for maternal insulin treatment based on fetal mutation status. However, a recent study suggests macrosomia and miscarriage rates may be increased with this strategy. Recent demonstration of transplacental transfer of sulfonylureas also raises questions as to when insulin should be initiated in sulfonylurea-responsive forms of monogenic diabetes. Pregnancy represents a challenge in management of monogenic diabetes, where factors of maternal glycemic control, fetal mutation status, and transplacental transfer of medication must all be taken into consideration. Guidelines for pregnancy affected by monogenic diabetes will benefit from large, prospective studies to better define the need for and timing of initiation of insulin treatment.