Disorders of carbohydrate metabolism not only reduce the quality of life of patients of reproductive age due to violations of the regularity of menstruation, anovulation and other clinical manifestations, but also affect the stages of pregnancy planning, affect the course of pregnancy and play an important role in the postpartum period. In overweight women, the presence of insulin resistance (IR), as well as existing disorders of carbohydrate metabolism, a conscious approach to pregnancy planning with maintaining targets before and throughout pregnancy is extremely important. The particular importance of a responsible approach is necessary due to the fact that glycemic disorders in both hyperand hypoglycemia are associated with risks on the part of the patient and the unborn child. Infertility, miscarriage, the risk of preeclampsia and eclampsia, as well as a high risk of birth injury (in relation to both mother and child) due to the peculiarities of childbirth with a large fetus are common among patients with impaired carbohydrate metabolism. Among all disorders of carbohydrate metabolism in patients of reproductive age, the most common are such as prediabetes, gestational diabetes mellitus, type 2 diabetes mellitus, all of which are associated with IR. Polycystic ovary syndrome, one of the main pathogenetic links of which is also IR, can be outlined separately. The use of metformin as a drug aimed at reducing IR is pathogenetically justified in such situations, however, despite the evidence of the safety of metformin presented by a large number of studies, there are no unified recommendations on dosage, timing and duration of metformin administration.