The main mechanism of gestational diabetes mellitus (GDM) is insulin resistance, therefore using metformin as a medicine reducing insulin resistance appears to be promising. Currently, the majority of medical associations do not recommend using metformin during pregnancy as the first-line of therapy when the diet regimen is insufficient for glycaemic control. However, they do allow its administration if there is no possibility of insulin treatment. There is some evidence which suggests that using metformin during pregnancy is not related to an increased risk of obstetric complications during delivery and that its influence on the foetus can be beneficial. Since metformin crosses the placenta, the major argument for cautious use of this drug are the potential long-term effects of the treatment for the child and its development in later life. In this article, the authors attempt to discuss the use of metformin during pregnancy and the safety of the treatment in the light of current studies and recommendations.
Keywords: GDM; diabetes mellitus; metformin; pregnancy.