Pregnancy course and outcomes in patients with non-insulin dependent gestational diabetes mellitus: An observational cohort study

Abstract

Background. Gestational diabetes mellitus is the most frequent metabolic disorder during pregnancy. Its prevalence is steadily increasing worldwide. In the setting of hyperinsulinism, this pathology may cause various structural and functional changes in the placenta, as well as a reduction in oxygen supply to the fetus. This may result in fetal hypoxia and increased risk of fetal growth restriction. Therefore, research into the specific features of gestation course in patients with gestational diabetes mellitus in order to prevent its complications appears relevant. Objective. To study the specific features of gestation, delivery, and perinatal outcomes in patients with non-insulin dependent gestational diabetes mellitus. Methods. We conducted an observational cohort study of the case histories of 120 women with singleton pregnancies of the second and third trimesters with diagnosed non-insulin dependent gestational diabetes mellitus, their labor and delivery records, and the medical records of the newborns. All the patients were managed at the Ural Research Institute of Maternity and Child Care during 2021–2023. The main group comprised 70 patients whose pregnancy was complicated by sub- and decompensated forms of placental insufficiency. The comparison group comprised 50 pregnant women without pathologies of the fetoplacental complex. The obstetric history, gestation course of the present pregnancy and its outcomes, as well as the condition of the newborns, were analyzed. The obtained data were processed by the methods of variation statistics using Microsoft Excel spreadsheets (Microsoft, USA) and Statistica 13 (DellInc., USA) and MedCalc 15.8 (MedCalcSoftware, Belgium) applications. The null hypothesis was rejected at p > 0.05. Results. Gestational diabetes mellitus in previous pregnancies was statistically significantly less frequent in the main group (2.9% (n = 2)) than in the comparison group (18.0% (n = 9)) ( p > 0.05). Placental insufficiency in the main group was characterized by fetal growth restriction, which was associated with impaired uteroplacental blood flow in 58.6% (n = 41) of the cases. In the main group, the pregnancy ended in preterm delivery in 21.4% (n = 15) of the cases; in 78.6% (n = 55) of the cases, the delivery was at term. There were no preterm births in the comparison group, p > 0.05. Cesarean section was performed in 62.9% (n = 44) of patients in the main group, compared to 20.0% (n = 10) in the comparison group ( p > 0.05). Newborns of the main group required respiratory support more often (p > 0.05). Conclusion. The mechanism of placental insufficiency in patients with non-insulin dependent gestational disorders of carbohydrate metabolism remains to be elucidated. Further research should investigate the predictors of fetoplacental complex pathologies in this group of patients in order to reduce the number of perinatal complications.

Keywords

• gestational diabetes mellitus
• placental insufficiency
• fetal growth restriction
• perinatal outcomes