Gestational diabetes is also a strong risk factor for the development of diabetes mellitus at a later stage of life in previous GDM woman. Among all the risk factors of diabetes mellitus, the experience of gestational diabetes is the strongest one. The incidence of various forms of diabetes in this group balances from 10 to 60% over a period from 2 to 10 years.

The aim of this study is a comparison of the efficacy of life style modification and life style modification in conjunction with metformin administration, in a population of women, who had already experienced gestational diabetes.

Gestational diabetes mellitus (GDM) is one of the most frequent metabolic disorders occurring during pregnancy that complicates both, the course of pregnancy and the delivery and is also responsible for many fetal complications. Gestational diabetes is also a strong risk factor for the development of diabetes mellitus at a later stage of life in previous GDM woman. Among all the risk factors of diabetes mellitus, the experience of gestational diabetes is the strongest one. The incidence of various forms of diabetes in this group balances from 10 to 60% over a period from 2 to 10 years.

Presently, in the literature, there are described new, more efficient methods of diabetes prevention in groups with a high risk of this disorder, which involve both, a modification of the life style and pharmacotherapy. The use of metformin in patients with a impaired glucose tolerance, resulted in a ca. 30% reduction of the diabetes incidence rate.

The aim of this study is a comparison of the efficacy of life style modification and life style modification in conjunction with metformin administration, in a population of women, who had already experienced gestational diabetes.

Inclusion Criteria:

• GDM - experienced during pregnancy (diagnosis of GDM according to WHO-criteria)
• Breast-feeding of the newborn finished (lactation finished)
• Actual BMI >= 25 kg/ m2
• Written consent for participation in the study
• A hitherto prevailing good cooperation with the patient

Exclusion Criteria:

• Cholestasis during the past pregnancy
• Any hepatic diseases in the past (viral hepatitis, toxic hepatic damage,jaundice of unknown etiology)
• Serum ASPAT and/or ALAT level exceeding more than twice normal laboratory values
• Pregnancy planned during the coming two years
• Presence of contradictions for metformin administration according to demands of the Drug Admission Committee in Poland