The goal of this clinical trial is to see if diabetes in pregnancy can be treated with once daily dosing of insulin instead of once daily dosing plus insulin with meals. The main question this study aims to answer is:

1. Can a once daily dose of long-acting insulin control blood sugars as well as long-acting insulin plus meal-time insulin?
2. Do babies born to mothers who take one dose of long-acting insulin have more complications after birth than babies born to mothers who take long-acting and meal-time insulin? Researchers will compare one dose of long-acting insulin per day to this plus three doses of short-acting insulin with each meal to see if blood sugars are controlled.

Participants will send their blood sugar logs to the study staff weekly, instead of to their OB/GYN, for adjustments to their insulin dosing.

Purpose/Specific Aims

The purpose of this study is to determine if a single dose of long-acting insulin is non-inferior to long-acting insulin plus prandial insulin to manage diabetes in pregnancy, measured by a composite neonatal outcome of NICU admission, neonatal hyperglycemia, neonatal hypoglycemia, large for gestational age, shoulder dystocia, hyperbilirubinemia, stillbirth, and neonatal death.

A. Objectives:

This study aims to compare neonatal outcomes of patients with diabetes in pregnancy to determine if a single dose of long-acting insulin is non-inferior to long-acting insulin plus prandial insulin.

B. Hypotheses / Research Question(s):

The hypothesis is that once-daily long-acting insulin glargine is noninferior to long-acting insulin glargine in combination with prandial short-acting insulin lispro, which is the current standard of care at our institution, for glycemic management of gestational diabetes mellitus and type 2 diabetes mellitus in pregnancy, as measured by a composite neonatal outcome. The composite outcome includes NICU admission, neonatal hyperglycemia, neonatal hypoglycemia, large for gestational age, shoulder dystocia, hyperbilirubinemia stillbirth, and neonatal death, which are associated with inadequate glycemic management during pregnancy.

Research Procedure:

Individuals will be recruited for the study during routine prenatal care visits or during initial, standard of care consults with Robert Wood Johnson or NYU Langone Maternal Fetal Medicine Specialists when insulin use is suggested for glycemic management. Gestational age at enrollment will vary from patient to patient, but all patients will be enrolled when insulin is clinically indicated to manage their diabetes. If patients choose to participate in the study, they will be randomized to standard of care (long-acting insulin glargine plus prandial insulin lispro) or the experimental group (long-acting insulin glargine only). This study is a noninferiority study between standard of care dosing strategies. This question is best investigated via a noninferiority design, given the potential to improve the currently accepted treatment by reducing patient burden. During this initial consult, a review of medical records is completed, regardless of study participation.

After randomization, both groups will receive dosing instructions per the Insulin Dosing Algorithm. The study utilizes a similar process to the MFM clinical workflow. Patients test their blood glucose at home, and send their blood glucose logs to MFM nurse or study team member, which includes an MFM fellow. If insulin dose adjustments are needed due to hyper- or hypoglycemia, these dose modifications will be made based off the Insulin Dosing Algorithm (Figure 1), and be recorded in the Insulin Dosing Log and communicated with the patients.

Patients will remain in their randomized group unless participation in the experimental group with insulin glargine alone is not sufficient to achieve glycemic targets, as evidenced by three dose increases with persistent hyperglycemia. In that case, patients revert to standard of care group but remain in the study.

The final study procedure is data abstraction and survey administration following childbirth. The Delivery Outcomes form on REDCap will be utilized to abstract relevant maternal and neonatal outcomes from the labor and delivery hospitalization, as well as any hospitalizations indicative of maternal complications prior to childbirth. Finally, the Diabetes Treatment and Satisfaction Questionnaire - Status (DTSQs) will be administered around the time of delivery, optimally at 38 weeks gestation to assess differences in perspective based on frequency of insulin injection between the two groups. This survey has been well-validated for assessing patient satisfaction with insulin treatment. Importantly, the DTSQs is appropriately sensitive to detect changes based on this study's independent variable, as it has been used in a similar study to analyze satisfaction changes in standard insulin versus analogue insulins, as well as changes in long-term and short-term insulin. Study participation ends with the completion of the DTSQs.

Inclusion Criteria:

• Diagnosed with type 2 diabetes mellitus or A2 gestational diabetes mellitus requiring insulin use during pregnancy
• Aged between 18-50
• Speak English or Spanish

Exclusion Criteria:

• Pre-existing use of insulin
• Gestational Age > or = 35w0d
• Planning to follow-up with a doctor not associated with RWJ Barnabas or NYU Langone Health and/or deliver at a hospital other than RWJUH or NYU
• Unwilling or unable to upload or email weekly blood sugar logs
• Contraindication to Lispro or Lantus insulin, or patient chooses to not utilize insulin therapy
• Fetal anomaly present