The national prevalence of preexisting diabetes among women with live births was 0.9% in 2016. Uncontrolled diabetes in pregnancy can lead to preeclampsia, cesarean delivery, preterm delivery, significant overgrowth in the child, and congenital defects. Diabetes management regimens can vary depending on preconception, pregnancy, or postpartum stage.

The Journal of the American Medical Association has published a clinical review about preexisting diabetes in pregnancy. The authors, all affiliated with leading health care centers in the United States, review current recommendations and encourage a multidisciplinary approach to care.

The American Diabetes Association (ADA) recommend women who are planning to become pregnant have hemoglobin A1c levels of less than 6.5% at conception, and maintain levels less than 6% during pregnancy. Preconception, clinicians should screen women for comorbid retinopathy, neuropathy, and obstructive sleep apnea. In women with chronic hypertension and diabetes, the ADA recommends a blood pressure target of 120/80-105 mm Hg to avoid fetal growth impairments.

In pregnant women with preexisting diabetes, the first line therapy for glucose management is insulin. Women should target fasting glucose levels of less than 95mg/dL, 1-hour postprandial glucose readings of lower than 140mg/dL, and 2-hour postprandial glucose below 120mg/dL. Glucagon administration is safe in pregnancy.

Pharmacists should note that angiotensin-converting enzyme inhibitors, statins, sulfonylureas, dipeptidyl peptidase-4 inhibitors (DPP4), glucagon-like peptide 1 (GLP-1) receptor agonists, and sodium glucose-cotransporter 2 inhibitors (SGLT), should be discontinued during pregnancy. They should also note that while evidence that angiotensin-converting enzyme inhibitors, statins, sulfonylureas must be discontinued is strong, with the newer agents, researchers are accruing safety data and this recommendation may change. Ideally, women would discontinue these drugs 3 months before conception.

As noted, diabetes increases risk of preeclampsia. After 12 weeks of gestation and ideally before week 16, obstetricians should prescribe low-dose aspirin (81 to 100 mg daily) to prevent preeclampsia.

Due to high insulin sensitivity postpartum, women will need less insulin. Insulin dose can be reduced by 50% in type 1 diabetics and may be stopped in type 2 diabetics. Non obese women who are breastfeeding need about 500 kcal/day more compared to the pre-pregnancy state. Metformin is safe during lactation.

Use of a long acting reversible contraceptive, such as implantable progestin or an intrauterine device, is safe during lactation and does not affect glycemic control.

Uncontrolled glycemic levels can have negative outcomes on maternal and neonatal health. Management of comorbid conditions, medication regimens, and optimal glycemic control are required to prevent serious complications during and after pregnancy.


Reference

Alexopoulos A-S, Blair R, Peters AL. Management of Preexisting Diabetes in Pregnancy: A Review. JAMA. 2019;321(18):1811-1819. doi:10.1001/jama.2019.4981