Inhaled Insulin vs Rapid-acting Injections for Post-meal Glucose Control in Women With Gestational Diabetes

Inclusion Criteria 1. Ability to provide informed consent for study participation 2. Age ≥18 years and \<41 years old 3. Singleton pregnancy at 24-34 weeks gestation 4. Diagnosis of GDM via standard 1-step or 2-step criteria 5. Treated with an insulin regimen that includes a RAA bolus of any type for breakfast, with a dose \<20 units 6. Pre-pregnancy or first trimester body mass index (BMI) 25-45 7. Investigator believes that the protocol can be safely conducted by the participant 8. Able to read and speak English Exclusion Criteria 1. Type 1 diabetes or type 2 diabetes 2. HbA1c ≥ 6.5%, FBG ≥125 mg/dl or 2-hr glucose ≥200 mg/dL on 75g OGTT, or random plasma glucose ≥200 mg/dL (consistent with pre-existing diabetes and not GDM diagnosis) 3. Current use of any non-insulin glucose lowering medication 4. Using TI (Afrezza), regular insulin, or ≥20 RAA units at breakfast (NPH is permissible) 5. Peak expiratory flow \<80% predicted as measured by peak flow meter 6. Recent history of asthma (defined as using any medications to treat asthma within the last year), chronic obstructive pulmonary disease (COPD), or any other clinically important pulmonary disease (e.g., cystic fibrosis or bronchopulmonary dysplasia), or significant congenital or acquired cardiopulmonary disease as judged by the Investigator 7. Smoking (includes cigarettes, cigars, pipes, and/or vaping devices) within 90 days prior to screening 8. History or current diagnosis of lung cancer 9. Current or anticipated use of oral, inhaled or injectable glucocorticoids during the time period of the trial (topical glucocorticoid use is acceptable) 10. Renal or hepatic impairment that in the investigator's judgment poses a safety risk for the study participant 11. Recurrent Level 2 (blood glucose \<54 mg/dL) or Level 3 severe hypoglycemia events 12. Current use of non-cardio-selective beta blockers 13. Being a member of the study team, having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study Investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial