The Effect of a Low Glycemic Index Diet on Blood Sugar Control in Pregnant Women at Risk for Gestational Diabetes

Study Overview
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Brief Summary
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Gestational diabetes mellitus (GDM) is a condition in which high blood sugar levels occur during pregnancy. GDM increases the risk of medical complications during pregnancy which may harm the mother and her baby. Since treating GDM to reduce blood sugar reduces the risk of harm, all pregnant women are screened for GDM using a glucose challenge test (GCT). We think that a diet containing low glycemic index foods could help keep blood sugar levels normal during pregnancy and therefore prevent GDM. Thus, the purpose of this study is to see if a diet containing low glycemic index foods will reduced blood sugar after the GCT and reduce the prevalence of GDM in women at high risk for the development of GDM.

Official Title
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The Effect of a Low Glycemic Index Diet on Blood Sugar Control in Pregnant Women at Risk for Gestational Diabetes

Conditions
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Diabetes, Gestational

Intervention / Treatment
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* Other: Nutrition education


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Attending Mt. Sinai Maternal Fetal Medicine Unit Any ONE of: body mass index >=25 kg/m^2 OR age >=35 years OR high risk ethnicity (Asian, South Asian, Hispanic, African, Aboriginal) Exclusion Criteria: Have pre-existing diabetes (type 1 or type 2) before becoming pregnant Acute or chronic illness which may affect carbohydrate metabolism Language/literacy barriers which cannot be overcome via available resources >16 weeks gestation

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: High fiber<br>High fiber carbohydrate foods with a high / medium glycemic index. Whole wheat bread and/or brown rice are provided to subjects if they wish. Subjects are provided with a list of other recommended carbohydrate foods. | Other: Nutrition education<br>* Group nutrition classes supplemented by handouts and provision of key study foods.<br>|
| Active Comparator: Low GI<br>Carbohydrate foods with a low glycemic index. Low GI rice and whole grain bread provided to subjects if they wish. Subjects are provided with a list of recommended foods. | Other: Nutrition education<br>* Group nutrition classes supplemented by handouts and provision of key study foods.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum glucose concentration 1hr after glucose challenge test |  | 26 weeks gestation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| GCT outcome | ie. normal, borderline, abnormal | 26 weeks gestation | 
| GDM outcome | Presence or absence of gestational diabetes | 26 weeks gestation | 
| Maternal weight |  | At EACH of the following times: 12, 16, 20, 24, 28, 32, 36 and 40 weeks gestation | 
| Mode of delivery | Normal or cesarean section | At time of birth of baby | 
| Presence of birth trauma |  | At time of birth of baby | 
| Weight of baby |  | At time of birth of baby | 
| Presence of macrosomia |  | At time of birth of baby | 
| presence of large for gestational age baby |  | At time of birth of baby | 
| Presence of small for gestational age baby |  | At time of birth of baby | 
| food frequency questionnaire |  | at 12 weeks and 26 weeks gestation | 
| Acceptability of study foods |  | 26 weeks gestation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Randomized clinical trial, Gestational diabetes, Carbohydrates, Glycemic index