Currently, there is a steady increase in the incidence of diabetes mellitus (DM) in the global population, which causes an increase in maternal and perinatal mortality. Children born to mothers with DM have a high risk of not only congenital abnormalities, but also cardiovascular and metabolic disorders in later life. Fetal growth is determined by both the metabolic and nutritional status of the mother, and the placental nutrient transfer capacity. Pregnancy complicated by DM is associated not only with overgrowth of the fetus, but also with the excess deposition of metabolites in the placenta. The role of disorders of carbohydrate metabolism, obesity and other factors in relation to the function of the placenta and fetal growth remains not fully understood. This review provides an overview of the literature on the placental complex status in pregnancy complicated by obesity, as well as pre-gestational and gestational types of DM. The focus is on three key substrates in these conditions: glucose, lipids, and amino acids, and their influence on placental metabolic activity and on the fetus. Improved knowledge of morphology and understanding of changes in the function of the placenta that lead to abnormal growth of the fetus will allow for the development of new therapeutic approaches to improve the outcomes of pregnancy, maternal and child health.

Hypothesis/aims of study. Diabetes mellitus (DM) is associated with an increased risk of obstetric complications, including preterm birth (PB). The incidence rate of PB in women with DM is higher than in the general population and amounts to 3040%. Nevertheless, there are still open questions on the structure of PB, pharmacological approaches to its prevention and treatment, as well as the feasibility of prolonging the timing of glucocorticoid therapy to reduce perinatal morbidity and mortality. The objective of this study was to research the features of structure and clinical approaches in the case of PB in women with different types of DM, based on a literature review. Study design, materials and methods. The study was performed using literature search, screening, data extraction, and analysis of publications collected in world databases such as MEDLINE, EMBASE, CNKI, and Cochrane. Results. The rate of PB is the highest in women with pregestational DM: 2130% in type 1 DM and 1940% in type 2 DM. The incidence of PB in gestational DM (710%) is almost equal to the general population level (79%) and depends on the type of diabetes therapy: insulin 16%, diet 7%. Risk factors for PB in women with DM are poor glycaemic control, microvascular complications of DM, hypertension, obesity, infection, age, fetal macrosomia, polyhydramnios, and congenital malformations. Adequate glycemic control from early gestation is an important condition for PB prevention. The structure of PB in patients with pregestational DM changes due to an increase in both spontaneous and induced PB proportions. The most common indications for early delivery in DM are preeclampsia, premature placental abruption, impaired renal function in diabetic nephropathy, severe forms of carbohydrate metabolism disorders, diabetic fetopathy, and fetal distress. The risk of fetal respiratory distress syndrome in newborns of mothers with DM is higher than in the general population. The maturity of the lungs of a newborn may be insufficient, even in the case of term delivery. The use of antenatal corticosteroids is effective prophylaxis of respiratory disorders. However, these corticosteroids can increase the risk of neonatal hypoglycemia. Conclusion. Despite the term weight and height, the newborn of a mother with DM may remain immature, therefore, delivery at term is recommended. The gestational age, until which it is advisable to prescribe corticosteroids for pregnant women with DM, and the mode of delivery in the case of PB, remain a matter of debate.

Objective: To assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (fb-hCG) in cases of diabetic pregnancy, to determine whether these biomarkers can be considered significant predictors for macrosomia, preeclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth in mothers with different types of pregestational diabetes mellitus (DM). Methods: It was a retrospective cohort study. Study groups were presented: type 1 DM (n = 100), type 2 DM (n = 50), and controls (n = 25). At 11 + 0 to 13 + 6 week’s gestation, we recorded maternal characteristics and medical history, and performed a combined test for the detection of risk of chromosomal abnormalities. To assess the performance of the markers in the prediction of the main obstetrical complications (PE, IUGR, preterm birth, and macrosomia), receiver-operating characteristic (ROC) curves were produced and area under the curves was calculated. Results: The study has shown that DM is associated with a high rate of perinatal complications: PE, IUGR, macrosomia, and preterm birth. The median level of PAPP-A was significantly lower in case of type 1 DM- 0.89 (inter quartile range (IQR), 0.51–1.1), and type 2 DM-0.88 (IQR, 0.42–1.15) compared to the unaffected group 1.03 (IQR, 0.96–1.12; p = .025). There were no significant differences in the fb-hCG multiples of the normal median (MoM; p = .14) between the diabetic and unaffected groups. More significant results were obtained when calculated by percentile: in diabetic pregnancies, PAPP-A and fb-hCG MoMs values were lower in the 5–10% ranges and higher in the 95% range, compared to the control group. ROC-analysis did not show any significant data that first-trimester PAPP-A and fb-hCG serum levels are predictors for PE, IUGR, macrosomia, and preterm birth. Conclusion: The routine first-trimester serum screening of fetal Down syndrome cannot be used as a tool of risk identification for PE, IUGR, macrosomia, and preterm birth in case of diabetic pregnancy.

Objectives: Diabetes mellitus (DM) in pregnancy and gestational diabetes remain a considerable cause of pregnancy complications, and fetal macrosomia is among them. Insulin, insulin-like growth factors (IGFs), and components of their signal-transduction axes belong to the predominant growth regulators and are implicated in glucose homeostasis. This study aimed to evaluate the available evidence on the association between the IGF axis and fetal anthropometric parameters in human diabetic pregnancy. Methods: PubMed, Medline, Web of Science, and CNKI databases (1981–2021) were searched. Results: Maternal and cord serum IGF-I levels are suggested to be positively associated with weight and length of neonates born to mothers with type 1 DM. The results concerning IGF-II and IGFBPs in type 1 DM or any of the IGF axis components in type 2 DM remain controversial. The alterations of maternal serum IGFs concentrations throughout diabetic and non-diabetic pregnancy do not appear to be the same. Maternal 1st trimester IGF-I level is positively associated with fetal birth weight in DM. Conclusions: Research on the IGF axis should take gestational age of sampling, presence of DM, and insulin administration into account. Maternal 1st trimester IGF-I level might become a predictor for macrosomia development in diabetic pregnancy.