Comparison of Hypoglycemia and Safety Outcomes With Long-Acting Insulins Versus Insulin NPH in Pregestational and Gestational Diabetes

Background: Current guidelines from the American College of Obstetricians and Gynecologists recommend insulin as the standard therapy for treatment of pregestational and gestational diabetes (PGDM and GDM). However, the guidelines do not specify which type(s) of insulin to utilize. Additionally, there are limited published data regarding safety parameters of insulin in this population. Objective: To evaluate if insulin glargine or detemir (long-acting insulin) results in less hypoglycemia, hospitalizations, or delivery complications compared with intermediate-acting insulin neutral protamine Hagedorn (NPH) in PGDM and GDM. Methods: This single-center, retrospective, observational cohort study included pregnant women who were 18 years or older with PGDM or GDM and received insulin therapy during pregnancy at an outpatient obstetric clinic. The primary outcome was the frequency of hypoglycemia (BG < 60 mg/dL). Secondary outcomes included emergency department visits and hospitalizations, delivery complications, and the duration of time at glycemic targets during pregnancy. Results: A total of 63 patients were included for evaluation. There was no significant difference in the frequency of hypoglycemia between the long-acting and NPH groups (4.4 vs 6.2 events per patient, respectively; P = 0.361). Patients receiving long-acting insulin had significantly more encounters with diabetes education (10.6 vs 5.1 visits per patient, P = 0.002) and more consistently provided glucose readings at their appointments (8.3 vs 4.8, P = 0.043). There was no difference in hospitalizations or maternal and neonatal complications. Conclusion and Relevance: Long-acting insulins did not reduce the frequency of hypoglycemia compared with NPH. The results of this study confirm the need for additional investigations with larger populations.