Intravenous Insulin Versus Subcutaneous Insulin Infusion in Intrapartum Management of Pregnant Women With Type 1 Diabetes Mellitus: A Randomized Trial
Phase: PHASE4
Conditions: Type 1 Diabetes, Pregnancy, High Risk
Sponsor: Gianna Wilkie

Title: Intravenous Insulin vs. Subcutaneous Insulin Infusion in Intrapartum Management of Type 
1 Diabetes Mellitus 
 
 
 
NCT Number: NCT04599075 
 
 
 
 
Date: June 6, 2024 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study Protocol/Methods 
We conducted a randomized clinical trial at a single tertiary care center in central 
Massachusetts from March 2021 until April 2023. Prior to study initiation, approval was 
obtained from the University of Massachusetts Chan Medical School institutional review board. 
Written informed consent was obtained from all participants before enrollment and patient safety 
data and trial progress was assessed via a Data Safety Monitoring Board with all reporting 
following Consolidated Standard of Reporting Trials guidelines. 
Inclusion criteria included pregnant patients aged 18 years or older with a known 
diagnosis of T1DM that were managed with CSII/insulin pump. All included participants had to 
obtain pregnancy and delivery care the study institution and had to be able to provide written 
informed consent in English or Spanish. Patients were not eligible if they were under the age of 
18 years old, had multiple gestations, had altered state of consciousness intrapartum, were 
critically ill requiring intensive care unit admission, at risk for suicide, presented with diabetic 
ketoacidosis on admission for delivery, had an intrauterine fetal demise prior to labor, fetal 
anomalies, or if the participant was unable to partake in their own care.  
All eligible participants were approached antenatally during routine prenatal care and 
consented for participation. Participants were then randomly allocated to either continuation of 
an intrapartum CSII/insulin pump or intravenous insulin infusion. Permutated block 
randomization with varying blocks sizes was used to stratify randomization by intrapartum 
glycemic management strategy (CSII vs. IV). The resulting group allocations were kept in 
sealed, opaque envelopes until opened by the provider at the time of randomization. Patients and 
providers were not blinded to randomization given active participation of providers and patients 
was needed in both study arms. Once admitted for labor, two separate intrapartum glycemic 
protocols were followed based on randomization category (Supplementary Figures 1 and 2).  

All medical records were reviewed for maternal demographics, clinical characteristics, 
and perinatal outcomes including primary and secondary outcomes. The primary outcome for the 
study was the first neonatal blood glucose level measured after birth. At our institution, it is 
policy that all neonates of mothers diagnosed with pre-gestational diabetes receive a heel-stick 
glucose measurement within the first 2 hours of life. Neonatal hypoglycemia was defined as 
blood glucose level less than 40 mg/dL, which prompts treatment and further monitoring at our 
study institution.18 In order to detect a 10 mg/dL difference in mean neonatal blood glucose 
levels between groups with a type 1 alpha error of 0.05 and 80% power with equal group sizes, 
35 participants in each group were needed for a total sample size of 70 patients.  
Secondary neonatal outcomes included mean neonatal glucose in the first 24 hours of life, 
neonatal hyperglycemia treatments including oral or intravenous treatment, 5 minute APGAR 
less than 7, NICU admission, neonatal birthweight, neonatal birthweight meeting large for 
gestational age criteria by Fenton growth calculator for preterm infants or World Health 
Organization growth calculator for term infants, or additional adverse neonatal outcomes 
including respiratory distress requiring intubation or continuous positive airway pressure 
(CPAP), hyperbilirubinemia, and neonatal cooling. Maternal secondary outcomes included 
intrapartum hypoglycemic events defined as blood glucose less than 60 mg/dL, intrapartum 
severe maternal hyperglycemic events defined as blood glucose greater than 200 mg/dL, 
development of diabetic ketoacidosis intrapartum, mode of delivery, shoulder dystocia at 
delivery, development of gestational hypertension or pre-eclampsia, maternal blood transfusion, 
and maternal intensive care unit admission.  
All summary data were collected and managed using REDCap tools hosted at UMASS 
Chan Medical School. Summary data are reported as frequencies for categorical variables and 

mean (standard deviation) or median (interquartile range) for continuous variables. All 
categorical variables were compared using Fisher exact test and Chi square testing where 
appropriate, while continuous variables were assessed for normality and t-tests or Wilcoxon rank 
sum tests were used where appropriate. For all analyses, a two-sided significance level of P<0.05 
was considered statistically significant. Analyses were performed using STATA/SE 17.0 
(StataCorp, College Station, TX).