This article reviews the literature on placental morphofunctional changes in placenta of patients with type 1 and type 2 diabetes mellitus and gestational diabetes mellitus. The detailed analysis of features of pathogenesis of various abnormalities of the fetoplacental complex depending on the type of diabetes, its influence on the formation of the placental vascular bed. The analysis of mechanisms of development of placenta formation disorders, pathologies of placental vascular bed, the role of hyperglycemia and hyperinsulinemia in villous maturation, placental weight gain, perinatal outcomes. The discussed anomalies have a significant impact on the fetoplacental complex, acting as epigenetic factors, forming the environment for the fetus, which may later affect the health of the unborn child. They lead to adverse perinatal outcomes, including high infant morbidity and mortality. Literature search was performed in Russian (eLibrary, CyberLeninka.ru) and international (PubMed, Cochrane Library) databases in Russian and English languages. The free access to the full text of the articles was in priority. The selection of sources was prioritized for the period from 2016 to 2020. However, due to the lack of knowledge of the chosen topic, the selection of sources was dated from 2001.

The review article presents data on the effects of obesity on the female reproductive system and offspring of mothers with overweight or obesity, such as infertility, miscarriages, premature birth, stillbirth, congenital anomalies and prematurity, as well as a high risk of cesarean section. Obesity accompanies polycystic ovary syndrome, worsening the metabolic profile and increasing the risk of developing depression and eating disorders. Maternal obesity and hyperglycemia are able to influence the formation of the fetus by epigenetic mechanisms without affecting the nucleotide sequences. Subsequently, the metabolic and cardiovascular risks increase in the descendants of obese or overweight mothers and gestational diabetes. Patients with obesity are characterized by a folic acid deficiency and a deficiency of the luteal phase. Exogenous administration of these substances improves pregnancy outcomes and prevents congenital malformations.