U-500R and aspart insulin for the treatment of severe insulin resistance in pregnancy associated with pregestational diabetes.

Severe insulin resistance as a complication of diabetes in pregnancy is seen with increasing frequency. Treatment with large doses of insulin (>300 units perday) can be practically difficult. A woman with preexisting Type 2 diabetes mellitus and poor glycemic control presented in early pregnancy requiring over 1000 units of insulin daily. She was transitioned to subcutaneous U-500 (concentrated regular insulin) in combination with a rapid-acting insulin analog achieving good glycemic control and good maternal and fetal outcomes. U-500R insulin in conjunction with a rapid-acting insulin analog can be used safely in early pregnancy to improve glycemic control in severe insulin resistance due to pregestational diabetes.