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Gestational Diabetes and Pharmacotherapy (GAP)

Gestational Diabetes and Pharmacotherapy (GAP) - A Randomized Controlled Trial Investigating Timing of Pharmacotherapy Initiation for Patients With Gestational Diabetes

Status
Active, not recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03527537
Acronym
GAP
Enrollment
416
Registered
2018-05-17
Start date
2021-05-04
Completion date
2026-10-01
Last updated
2026-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Gestational Diabetes

Brief summary

The goal of this study is to compare two different thresholds for initiation of medical treatment for GDM. Pregnant women diagnosed with GDM will be randomized to either start pharmacotherapy when they have reached at least 20% or at least 40% of capillary blood glucose (CBG) values above the target goal. The investigators hypothesize that a lower threshold of 20% elevated CBG levels, compared to 40%, will lead to lower rates of obstetric and medical complications.

Detailed description

Gestational diabetes mellitus (GDM) affects 5-8% of pregnant women, many of whom will require treatment beyond diet and exercise. Despite this high prevalence, there is no consensus regarding the glycemic threshold for conversion from diet to medical treatment for GDM. No randomized studies have been performed on how to define failure with diet and exercise and currently, the need to start insulin or oral hypoglycemic agents is at the provider's discretion. It is important to establish criterion of pharmacotherapy initiation for GDM in pregnancy as GDM under-treatment leads to increased rates of adverse obstetric outcomes associated with poor glycemic control including macrosomia, pre-eclampsia, cesarean delivery, shoulder dystocia, birth trauma, neonatal hypoglycemia and hyperbilirubinemia, childhood obesity and metabolic syndrome in the offspring. In contrast, overtreatment for women comes at increased cost due to overutilization of resources, increased expense, and adverse effects of the medications themselves. The goal of this study is to compare two different thresholds for initiation of medical treatment for GDM. Pregnant women diagnosed with GDM (N=416) will be randomized to either start pharmacotherapy when they have reached at least 20% or at least 40% of capillary blood glucose (CBG) values above the target goal. The investigators hypothesize that a lower threshold of 20% elevated CBG levels, compared to 40%, will lead to lower rates of obstetric and medical complications. Aim 1: Determine the effect of earlier insulin initiation (20% threshold) for GDM management on adverse neonatal and maternal outcomes associated with GDM. Hypothesis 1.1: The composite adverse neonatal outcome associated with GDM (LGA, macrosomia, birth trauma, preterm birth, neonatal hypoglycemia, and hyperbilirubinemia) will be lower in earlier insulin initiation compared with the active control group. Hypothesis 1.2: Preeclampsia and cesarean birth frequencies will be lower in earlier insulin initiation compared with the active control group. Hypothesis 1.3: The composite neonatal and maternal outcomes will not differ between racial and ethnic groups within each study group. Aim 2:Assess the safety of earlier insulin initiation in pregnant patients and their neonates. Hypothesis 2.1: The SGA rate will be higher in earlier insulin initiation compared with the active control group; however, in both groups it will be lower than the national rate of 10%. Hypothesis 2.2: Maternal hypoglycemia and perinatal death will not differ between groups. Aim 3:Determine the effect of earlier insulin initiation on patient-reported outcomes using standardized measures and qualitative interviews. Hypothesis 3: Anxiety, depression, perceived stress and diabetes self-efficacy will be better in patients randomized to earlier insulin initiation compared with the active control group.

Interventions

DRUGInsulin

Insulin may be administered base on glucose log values. The dosing of the insulin will be determined by the provider using typical management of gestational diabetes.

Sponsors

Medical College of Wisconsin
Lead SponsorOTHER
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
CollaboratorNIH

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

This will be a randomized, controlled trial of 284 women with a diagnosis of GDM. Women will be consented and randomized at the time of their diagnosis. All women with GDM will receive counseling regarding diet and exercise and instructions on self-monitoring blood glucose values. The investigators will apply cutoffs of 95 mg/dL for fasting and 120 mg/dL for 2-hour post-prandial levels. Once randomized, the first treatment arm will be assigned to a limit of 20% abnormal values before we start treatment and to titrate up dosages as needed, while using the 20% threshold of abnormal CBG values at each subsequent review of glucose log. To specify, if more than 20% of values for the week are elevated, treatment would be initiated. Once treatment is initiated, the dosage of medication will be adjusted with cutoff of 20% of abnormal values per week. The second treatment arm will utilize the same protocol, however, the limit to start medications or adjust dosages will be 40% abnormal values.

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No

Inclusion criteria

* Viable singleton pregnancy * Age \>= 18 years old * Diagnosed with gestational diabetes mellitus * Able to communicate in English

Exclusion criteria

* Pre-gestational diabetes * Significantly abnormal GDM testing, suggestive of the presence of pre-gestational diabetes, either with fasting values \>=126 mg/dL or 2-hour post-prandial levels \>=200 mg/dL * Patients who check blood sugars on average less than 2 times per day after appropriate counseling * Already started pharmacotherapy prior to referral to the study

Design outcomes

Primary

MeasureTime frameDescription
Composite Neonatal OutcomeThe data will be collected up to 6 weeks of lifeOur primary outcome will be a composite adverse neonatal outcome associated with gestational diabetes: large-for-gestational age macrosomia birth trauma preterm birth neonatal hypoglycemia hyperbilirubinemia

Secondary

MeasureTime frameDescription
Cesarean Delivery RateThe data will be collected up to 6 weeks postpartumOur secondary outcome will be to compare the rates of cesarean delivery between two thresholds for medical treatment initiation for GDM.
PreeclampsiaThe data will be collected up to 6 weeks postpartum

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 21, 2026