Fetal growth restriction in diabetic pregnancy: a retrospective single-center study

BACKGROUND: The high risk of adverse maternal and perinatal complications in patients with fetal growth restriction and diabetes mellitus requires a detailed assessment of the major risk factors and outcomes.

AIM: The aim of this study was to determine the main risk factors for fetal growth retardation in pregnant women with pregestational and gestational diabetes mellitus, and to assess obstetric and perinatal outcomes in these patients.

MATERIALS AND METHODS: We conducted a retrospective single-center cohort study at the premises of the Research Institute of Obstetrics, Gynecology and Reproductology named after D.O. Ott, Saint Petersburg, Russia. The study included 103 patients with type 1 diabetes mellitus, type 2 diabetes mellitus, or gestational diabetes mellitus with fetal growth retardation who delivered a singleton neonate from January 2017 to December 2021. Based on the antenatal diagnosis, the patients were divided into the following comparison groups: group I — early fetal growth retardation (n = 29), group II — late fetal growth retardation (n = 27), group III — small for gestational age (n = 47). Relative risk calculations were used to assess the contribution of risk factors and the risk of developing secondary outcomes.

RESULTS: Pregestational diabetes mellitus was the major risk factor for early fetal growth retardation development (relative risk 1.91; 95% confidence interval 1.04–3.50); especially type 1 diabetes mellitus (relative risk 1.64; 95% confidence interval 1.02–2.74) and more than 10 years of pregestational diabetes mellitus duration (relative risk 2.62; 95% confidence interval 1.12–6.17). Chronic hypertension increases the risk of early fetal growth retardation (relative risk 2.11; 95% confidence interval 2.21–3.68), while gestational hypertension was a significant risk factor for late fetal growth retardation development (relative risk 1.81; 95% confidence interval 1.01–3.70). Preeclampsia is associated with both early and late forms of fetal growth retardation. Maternal characteristics, such as age over 35 years, obesity, and in vitro fertilization pregnancy, increased the risk of early fetal growth retardation development. In turn, the presence of fetal growth retardation in patients with diabetes mellitus is associated with increased risk of cesarean section, prolonged stay of the newborn in the neonatal intensive care unit (≥5 days), low Apgar scores (<7 at the 5th minute), and neonatal hypoglycemia. Early fetal growth retardation is a significant risk factor for preterm birth (relative risk 6.23; 95% confidence interval 2.87–13.42) and fetal distress (relative risk 5.51; 95% confidence interval 2.28–13.33).

CONCLUSIONS: Being associated with a highly increased risk of adverse obstetric and perinatal outcomes, early fetal growth retardation in diabetic pregnancy is related to pregestational diabetes mellitus, especially type 1 diabetes mellitus, with a long history, as well as with hypertension in pregnancy.