The purpose of this study is to determine if taking insulin glargine twice a day instead of once a day will better manage pregestational diabetes in pregnant patients. Participants in this study will be randomly assigned to one of two groups: a group that takes insulin glargine once a day, and a group that takes it twice. Continuous glucose monitoring will be used to track blood sugar levels. The main question the study aims to answer is: Will using insulin glargine twice a day instead of once lead to a better glucose time in range?

Inclusion Criteria:

• Patients older than 18 years of age;
• The patient is fluent in English, physically and mentally able to understand the informed consent, and is willing to participate in this study;
• Type II diabetes mellitus requiring insulin;
• The patient is between 24 weeks 0 days and 28 weeks 0 days of gestation at the time of enrollment. Gestational age will be determined by last menstrual period, confirmed with a first trimester ultrasound, per the recommended guidelines by the American College of Obstetricians and Gynecologists.
• Currently using or willing to use a clinically indicated continuous glucose monitor for glycemic management

Exclusion Criteria:

• Known allergy or reaction to insulin glargine, or concurrent medical condition where the use of insulin glargine is contraindicated;
• Contraindication to CGM use, patient declines CGM use, or CGM not covered by patient's insurance;
• Known or suspected fetal anomaly or aneuploidy;
• Prisoners;
• Ongoing prenatal care outside EVMS or planned delivery outside Sentara Norfolk General Hospital.