Risk factors associated with preterm delivery in women with pregestational diabetes

The primary objective of this study was to compare the rates of spontaneous and indicated preterm delivery at less than 37 weeks of gestation. A second objective was to identify prenatal events associated with preterm delivery at less than 35 weeks of gestation in women with diabetes mellitus (DM).

A case-control study was conducted on 219 pregnant women with type 1 and type 2 DM, who were treated at a single medical center. The rate of preterm delivery at less than 37 weeks of gestation was determined. Preterm delivery was categorized into spontaneous and indicated for the purpose of the study. The distributions of relevant variables were compared between women who had preterm delivery at less than 35 weeks of gestation (n=16) and the controls (n=203).

Thirty-three women (15.1%) gave birth at less than 37 weeks of gestation. These patients were divided into two groups: seven cases (3.2% of the study sample) of spontaneous preterm delivery, and 26 cases (11.9%) of indicated preterm delivery. The presence of vascular disease (odds ratio [OR] 5.7; 95% confidence interval [CI] 1.3, 25.7), and pre-eclampsia/superimposed pre-eclampsia (OR 12.3; CI 3.1, 49.3) were found to be significantly associated with an increased risk of preterm delivery at less than 35 weeks of gestation.

In this case-control study, the presence of vascular disease, or pre-eclampsia/superimposed pre-eclampsia, was found to be correlated with an increase in the risk of preterm delivery at less than 35 weeks of gestation in diabetic pregnancies.