Metformin therapy in pregnancy [Zastosowanie metforminy w ciąży]

Gestational diabetes mellitus (GDM), i.e. a carbohydrate metabolism disorder at pregnancy, is one of the most common metabolic complications that occur during this period. Pancreatic b-cell dysfunction and insulin resistance during pregnancy are considered the main causes of the condition. It is currently estimated that GDM is confirmed in 1-25% of patients. Diagnosis and appropriate management allow to reduce the risk of complications in newborns and the perinatal mortality rate and also improve the prognosis for mother and offspring. Metformin is taken by many patients before pregnancy due to both previously diagnosed type 2 diabetes and in the treatment of prediabetes, obesity and polycystic ovary syndrome (PCOS) as part of therapy for insulin resistance. The use of metformin in pregnancy has been controversial for many years, particularly in terms of the safety of continuation of drug therapy. Available scientific data indicate both benefits and possible drug-related adverse effects in offspring of metformin-treated patients. This problem is related not only to patients with type 2 diabetes, but also to those with PCOS who are at increased risk of miscarriage, preterm delivery and the diagnosis of GDM in subsequent stages of pregnancy. Conclusive and uniform recommendations for the use of metformin at each stage of pregnancy have not been established yet due to the doubts about the mechanisms of action of the drug, particularly at the cellular level. This review paper presents the current state of knowledge on the use of metformin during pregnancy.