Use of medication for preventing diabetes in obese pregnant women

INTERVENTION: D02.078.370.141.450 Group Intervention: 104 pregnant women who will be randomized to 20 weeks of gestation, with a body mass index equal to or greater than 30 kg / m2, aged less than 18 years with screening for gestational diabetes mellitus in early negative pregnancy. They will be subjected to treatment with metformin hydrochloride use 500 mg orally after breakfast and dinner daily, until the end of pregnancy. All pregnant women in the study will receive standard monitoring being met by the nutritionist, nurses, physiotherapists and obstetricians. Control Group: 104 pregnant women who will be randomized to 20 weeks of gestation, with a body mass index equal to or greater than 30 kg / m2, aged less than 18 years with screening for gestational diabetes mellitus in early negative pregnancy. All pregnant women in the study will receive standard monitoring being met by the nutritionist, nurses, physiotherapists and obstetricians. CONDITION: Diabetes mellitus arises during pregnancy. Pregnancy complications. ; C13 ; O24.4 E00‐E90 PRIMARY OUTCOME: Reduction of cases of Gestational Diabetes Mellitus in obese pregnant women who have made the use of metformin hydrochloride, 2 times a day (breakfast and dinner), the realization of the reduction will be performed by biochemical analysis through oral test of glucose tolerance (OGTT ) to be held over the gestational trimesters. It expects a 35% effectiveness in reducing cases of Gestational Diabetes Mellitus which will be proven through statistical tests and comparing the concentrations in the OGTT test and control groups. SECONDARY OUTCOME: Decreased neonatal hypoglycemia in infants of obese pregnant women who have made the use of metformin hydrochloride during pregnancy. For evaluation of this variable will be held plasma glucose dosage of newborns according to protocol guidelines of the Brazilian Society of Pediatrics. For realization of the expected outcomes will be performed statistical tests and comparing the concentrations of plasma glucose in babies of mothers of test and control groups. INCLUSION CRITERIA: With obesity diagnosis of pregnant women will be selected according to the criteria of the World Health Organization with BMI or greater than 30 kg / m2; aged over 18 years; singleton pregnancy; with screening for gestational diabetes mellitus (GDM) at the beginning of the negative pregnancy; gestational age less than 20 weeks; no pathology that interferes with glucose metabolism; no hypersensitivity to metformin hydrochloride or important drug allergy; history or presence of liver disease; renal or gastrointestinal or other conditions that interfere with the absorption, distribution, excretion or metabolism of the drug.