Risk factors for pre-eclampsia in women with type 1 diabetes
Primiparity and diabetic vasculopathy appear to be strongly related to the development of pre-eclampsia (PE) in women with type 1 diabetes mellitus (T1DM), as reported in a study. Other risk factors include pre-existing hypertension, higher gestational weight gain (GWG), and higher HbA1c and triglyceride levels in all three trimesters.
The prospective, nested case–control study included 165 women with T1DM. Of these women, 141 were normotensive, eight had gestational hypertension (GH) and 16 had PE.
Clinical data were collected at three timepoints: the first trimester (<12th week), mid-pregnancy (20 to 24 weeks) and just prior to delivery (34 to 39 weeks). Insulin resistance in the first trimester was assessed using the estimated glucose disposal rate formula. Researchers performed logistic regression analysis to identify factors associated with PE and GH.
All cases of PE were diagnosed in primiparous women. Vasculopathy emerged as the strongest determinant of PE (odds ratio [OR], 10.8; p=0.0001), followed by a history of chronic hypertension (OR, 6.05; p=0.004) and diabetes duration (OR, 1.11; p=0.009).
However, in an analysis adjusting for the presence of vasculopathy, the association of PE with chronic hypertension and diabetes duration disappeared.
PE was also associated with higher GWG, and this relationship remained significant even after adjustment for first trimester body mass index (OR, 1.14; p=0.02). On the other hand, the association of both systolic and diastolic blood pressure (assessed in the first trimester) with PE was no longer observed following adjustment for the presence of chronic hypertension.
Other factors significantly linked to PE were HbA1c levels in all trimesters (first trimester: OR, 1.38; p=0.04; second trimester: OR, 2.76; p=0.002; third trimester: OR, 2.42; p=0.005), triglyceride levels in all trimesters (first trimester: OR, 5.32; p=0.005; second trimester: OR, 2.52; p=0.05; third trimester: OR, 2.28; p=0.001) and estimated glucose disposal rate (OR, 0.66; p=0.003).
Of note, greater triglyceride levels increased the risk of PE regardless of HbA1c levels.
None of the analysed factors showed any association with GH.