Predictors of preeclampsia in women in the Metformin in Gestational Diabetes(Mig) study

Abstract

Background: Gestational Diabetes Mellitus (GDM), maternal obesity and pregnancy weight gain are associated with an increased risk of developing Preeclampsia (PE). The aim of this study was to examine the predictors of PE in women commencing pharmacotherapy for GDM in the Metformin in Gestational diabetes trial. Methods: Descriptive and logistic regression analyses examined the relationship between maternal enrolment characteristics and later development of PE. Results: 46 (6.3%) of 703 women developed PE. At enrolment ((30 (SD3.2) weeks gestation), women who later developed PE had higher HbA1c (6.14% (95%CI 5.84, 6.45) vs. 5.73% (95%CI 5.67, 5.78), P=0.003), fasting triglycerides (2.93 mmol/L (95%CI 2.57, 3.29) vs. 2.55mmol/L (95%CI 2.47, 2.62), P=0.03) and blood pressure. Their infants were born 9 days earlier (P<0.001) but were otherwise not different. In univariate analysis, the strongest positive predictors for PE were Polynesian ethnicity (OR 2.75 (95%CI 1.48, 5.09), P=0.001), personal or family history of PE (OR 2.65 (95%CI 1.36, 5.16), P=0.004), maternal HbA1c (OR 1.96 (95%CI 1.35, 2.89), P<0.001), triglycerides (OR 1.45 (95%CI 1.07,1.97), P=0.002), and weight gain from early pregnancy (OR 1.09 (95%CI 1.03,1.17), P=0.01). HDL-C was a negative predictor of PE (OR 0.29 (95%CI 0.09, 0.94), P=0.04). Following adjustment for Polynesian ethnicity and personal or family history of PE, and when further adjusted for HbA1c or early pregnancy BMI, these variables remained significant. Conclusion: Treatment allocation and BMI were not associated with risk of PE. Personal or family history of PE, Polynesian ethnicity, degree of hyperglycemia, maternal triglycerides and weight gain prior to treatment signal increased risk of subsequent PE in women needing pharmacotherapy for GDM.