orals Australasian Diabetes in Pregnancy Annual Scientific Meeting 2013

Predictors of preeclampsia in women in the Metformin in Gestational Diabetes (MiG) study (#15)

Helen L Barrett 1 2 3 , Marloes Dekker Nitert 3 4 , David McIntyre 4 5 , Karin Lust 1 4 , Leonie K Callaway 1 4 , Bill Hague 6 , Janet Rowan 7
  1. Royal Brisbane and Women's Hospital , Herston, QLD, Australia
  2. Adult Cystic Fibrosis Centre, Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia
  3. Respiratory, Mater Health, South Brisbane, QLD, Australia
  4. Faculty of Medicine, University of Queensland, Herston, QLD, Australia
  5. Mater Research Institute - The University of QLD, Brisbane, QLD, Australia
  6. School of Paediatrics and Reproductive Health, Robinson Institute and Discipline of Obstetrics & Gynaecology, University of Adelaide, Adelaide, SA, Australia
  7. National Women's Health, Auckland, New Zealand

Gestational diabetes mellitus (GDM) is associated with an increased risk of developing preeclampsia (PE)  and treatment of GDM has been shown to reduce PE rates 1. Increased risk of PE has previously been related to maternal hyperglycaemia 2 , obesity 3  and hypertriglyceridaemia 4  . 

Aim: To examine the predictors of PE in women commencing pharmacotherapy for GDM in the MiG study.

Methods: Women with GDM were randomly assigned metformin or insulin in the MiG study 5 . At enrollment (commencement of pharmacotherapy) fasting maternal bloods were taken. Descriptive and logistic regression analyses were undertaken to examine the relationship between maternal characteristics at enrollment and the later development of PE. Diagnosis of PE was according to SOMANZ guidelines. Data are expressed at mean (95%CI) or n(%).

Results: 46 women (6.3%) were diagnosed with PE. Seven of these women had a preceding diagnosis of gestational hypertension. At enrollment (at an average of 30 weeks gestation), women who later developed PE had a higher HbA1c (6.14% (5.84 – 6.45) vs 5.73% (5.67 – 5.78), P = 0.003), fasting triglycerides (2.93 mmol/L (2.57 – 3.29) vs 2.55 mmol/L (2.47 – 2.62), P = 0.03) and higher blood pressure. The infants of women with PE were born 9 days earlier (P<0.001) and otherwise not different.

The strongest predictors of the development of PE in univariate analysis (per unit) were maternal HbA1c (OR 1.96 (1.35 – 2.89), P<0.001), maternal triglycerides (OR 1.45 (1.07 – 1.97), P=0.002), and maternal weight gain from early pregnancy (OR 1.09 (1.03 – 1.17), P=0.01), with the odds of developing PE increasing as these variables increase. In contrast, increasing maternal HDL-cholesterol was associated with lower odds of developing PE (OR 0.29 (0.09 – 0.94), P=0.04). Following adjustment for maternal age, parity, and smoking, these variables remained significant. When also adjusted for HbA1c, fasting triglycerides became non-significant. Treatement allocation to insulin or metformin was not associated with risk of PE.

Conclusion:

In women with GDM needing pharmacotherapy, increased risk of later PE is signaled by higher HbA1c and maternal triglycerides, lower maternal HDL-cholesterol and greater weight gain in early pregnancy.

  1. Crowther CA, et al., Effect of Treatment of Gestational Diabetes Mellitus on Pregnancy Outcomes. NEJM, 2005. 352(24): p. 2477-86.
  2. Carr, D.B., et al., Gestational diabetes or lesser degrees of glucose intolerance and risk of preeclampsia. Hypertension in pregnancy : official journal of the International Society for the Study of Hypertension in Pregnancy, 2011. 30(2): p. 153-63.
  3. El-Chaar, D., et al., The impact of increasing obesity class on obstetrical outcomes. J Obstet Gynaecol Can, 2013. 35(3): p. 224-33.
  4. Zhou, J., et al., Combination of lipids and uric acid in mid-second trimester can be used to predict adverse pregnancy outcomes. J Matern Fetal Neonatal Med, 2012. 25(12): p. 2633-8.
  5. Rowan, J.A., et al., Metformin versus insulin for the treatment of gestational diabetes. N Engl J Med, 2008. 358(19): p. 2003-15.