Importance:
The presence of preexisting type 1 or type 2 diabetes in pregnancy increases the risk of adverse maternal and neonatal outcomes, such as preeclampsia, caesarian section, pre-term delivery, macrosomia and congenital defects. Approximately 0.9% of the 4,000,000 births in the United States are complicated by preexisting diabetes.
Observations:
Women with diabetes have increased risk for adverse maternal and neonatal outcomes and similar risks are present for either type 1 or type 2 diabetes. Both forms of diabetes require similar intensity of diabetes care. Preconception planning is very important to avoid unintended pregnancies, and to minimize risk of congenital defects. Hemoglobin A1c goal at conception is <6.5% and during pregnancy is <6.0%. It is also critical to screen for and optimize comorbid illnesses such as retinopathy and nephropathy. Medications known to be unsafe in pregnancy, such as angiotensin-converting enzyme inhibitors and statins, should be discontinued. Obese women should be screened for obstructive sleep apnea, which is often undiagnosed and can result in poor outcomes. Blood pressure goals must be considered carefully, as lower treatment thresholds may be required for women with nephropathy. During pregnancy, continuous glucose monitor use can improve glycemic control and neonatal outcomes for women with type 1 diabetes. Insulin is first-line therapy for all women with preexisting diabetes; injections and insulin pump therapy are both effective approaches. Rates of severe hypoglycemia are increased during pregnancy; therefore glucagon should be available and close contacts trained in its use. Low-dose aspirin is recommended soon after 12 weeks of gestation to minimize the risk of preeclampsia. The importance of discussing long-acting reversible contraception before and after pregnancy cannot be overstated, to allow for appropriate preconception planning.
Conclusions and Relevance:
Preexisting diabetes in pregnancy is complex and is associated with significant maternal and neonatal risk, but optimization of glycemic control, medication regimens and careful attention to comorbid conditions can help mitigate these risks, and ensure quality diabetes care before, during and after pregnancy.