Gestational Diabetes Mellitus Trial (GDM)

• Composite neonatal morbidity (hypoglycemia, hyperinsulinemia, hyperbilirubinemia, birth trauma, neonatal mortality; death or stillbirth [ Time Frame: Delivery ] [ Designated as safety issue: No ]
• death or stillbirth [ Time Frame: Delivery ] [ Designated as safety issue: No ]

• - Composite neonatal morbidity (hypoglycemia, hyperinsulinemia, hyperbilirubinemia, birth trauma)
• - death or stillbirth

• large for gestational age [ Time Frame: Delivery ] [ Designated as safety issue: No ]
• macrosomia (birth weight > 4000 gm) [ Time Frame: Delivery ] [ Designated as safety issue: No ]
• delivery route [ Time Frame: Delivery ] [ Designated as safety issue: No ]
• neonatal fat mass [ Time Frame: Delivery ] [ Designated as safety issue: No ]
• neonatal mortality and morbidity [ Time Frame: Delivery ] [ Designated as safety issue: No ]

• - large for gestational age
• - macrosomia (birth weight > 4000 gm)
• - delivery route
• - neonatal fat mass
• - neonatal mortality and morbidity

Gestational diabetes mellitus (GDM) is a type of diabetes (high blood sugar) that occurs in pregnant women. This study will determine whether treating pregnant women who have mild GDM improves the health of their babies. The follow-up study will examine whether factors during the previous pregnancy (such as blood sugar during pregnancy) are associated with the woman and her child's health 4-9 years later.

Gestational diabetes mellitus is defined as glucose intolerance of variable severity with onset or first recognition during pregnancy. The definition applies regardless of insulin use for treatment or the persistence of the condition after pregnancy, and does not exclude the possibility that unrecognized glucose intolerance or overt diabetes may have preceded the pregnancy. Pre-existing diabetes substantially contributes to perinatal morbidity and mortality. The association of milder forms of gestational diabetes with adverse pregnancy outcomes, including morbidities such as macrosomia, birth trauma, and neonatal hypoglycemia, remains questionable. While it is likely that maternal glucose intolerances reflect a continuum of risk for adverse outcomes, it is not known whether there is a benefit to identification and subsequent treatment of mild glucose intolerance during pregnancy. This study will determine whether dietary treatment (and insulin as required) for mild GDM will reduce the frequency of neonatal morbidity associated with mild glucose intolerance.

Participants in this study will receive a 50-gram glucose loading test (GLT) between 24 and 30 weeks' gestation. Those with a positive GLT will receive a subsequent 3-hour oral glucose tolerance test (OGTT). Based upon these test results, women will be assigned to 4 groups. Women with a positive GLT and abnormal OGTT will be randomly assigned to receive either nutritional counseling and diet therapy (Group 1) or no specific treatment (Group 2a). Women with a positive GLT but normal OGTT will be enrolled in Group 2b for observation. Women with a negative GLT will be enrolled in Group 3 and will serve as a control group.

Women in Group 1 will receive formal nutritional counseling and will be instructed on the techniques of self blood glucose monitoring. Patients will take daily blood glucose measurements and will be seen at weekly study visits. The study will evaluate birth outcomes, including stillbirth, neonatal hypoglycemia, neonatal hyperinsulinemia, neonatal hyperbilirubinemia, and birth trauma.

The follow-up study will examine if blood sugar levels and treatments during pregnancy influence the health of the mother and child several years later. The study will also examine whether there is a genetic link to the health of the mother and child. The study visit will include blood pressure, body size measurements, blood draw and saliva collection, and questions related to the mother and child's health and environment.

• Behavioral: nutritional counseling
• Behavioral: self blood glucose monitoring

• Active Comparator: Nutritional counseling & self blood glucose monitoring
  Within one week of enrollment, women in the treatment group receive formal nutritional counseling and will be instructed on the technique of self blood glucose monitoring using a memory-based reflectance meter.
  Interventions:

  • Behavioral: nutritional counseling
  • Behavioral: self blood glucose monitoring
• No Intervention: No treatment
  This group will not receive any specific dietary therapy except for written information concerning general nutritional recommendations for normal pregnancy.

• Landon MB, Thom E, Spong CY, Gabbe SG, Leindecker S, Johnson F, Lain K, Miodovnik M, Carpenter M. A planned randomized clinical trial of treatment for mild gestational diabetes mellitus. J Matern Fetal Neonatal Med. 2002 Apr;11(4):226-31.
• Landon MB, Spong CY, Thom E, Carpenter MW, Ramin SM, Casey B, Wapner RJ, Varner MW, Rouse DJ, Thorp JM Jr, Sciscione A, Catalano P, Harper M, Saade G, Lain KY, Sorokin Y, Peaceman AM, Tolosa JE, Anderson GB; Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. A multicenter, randomized trial of treatment for mild gestational diabetes. N Engl J Med. 2009 Oct 1;361(14):1339-48.

Inclusion Criteria:

• Pregnant
• Gestational age at enrollment 24 - 31 weeks

Exclusion Criteria:

• Diabetes diagnosed prior to pregnancy
• Abnormal gestational diabetes (>= 135 mg/dl) testing prior to 24 weeks' gestation
• Gestational diabetes in a previous pregnancy
• History of stillbirth or fetal death
• Pregnancy with more than one fetus
• Known major fetal anomaly
• Current or planned corticosteroid therapy
• Asthma requiring medication
• Current or planned beta adrenergic therapy
• Chronic hypertension requiring medication within 6 months of or during pregnancy
• Chronic medical conditions such as HIV/AIDS, kidney disease, or congenital heart disease
• Hematologic or autoimmune disease such as sickle cell disease, other hemoglobinopathies, lupus, or antiphospholipid syndrome
• Maternal or fetal conditions likely to require preterm delivery, such as pre-eclampsia, preterm labor, or intrauterine growth retardation
• Previous or planned tocolytic therapy to induce labor or increase contraction strength