945-P: Elevated Blood Pressure in Pregnant Women with Gestational Diabetes According to the WHO Criteria: Importance of Obesity

Objective: Hypertension before and during early pregnancy has been associated with an increased risk of gestational diabetes mellitus (GDM) in retrospective analyses. We investigated the prospective blood pressure patterns in a population-based cohort of pregnant women, who were stratified according to their metabolic status in early 3^rd trimester.

Research Design and Methods: We recorded blood pressure longitudinally during pregnancy in 1,230 women from the Odense Child Cohort, Denmark. Fasting glucose and insulin were measured at gestational weeks 28-30. Metabolic status was evaluated according to the World Health Organization (WHO) 2013 threshold for GDM (GDM-WHO: fasting plasma glucose ≥5.1 mmol/l), insulin and homeostatic model assessment of insulin resistance (HOMA-IR). Relationships between metabolic status in 3^rd trimester and blood pressure trajectories throughout pregnancy were evaluated with adjusted linear mixed models.

Results: GDM-WHO prevalence was high, 40% (498/1,230). Significant associations between GDM-WHO and blood pressure were seen only in overweight women, with 2.48 (1.08; 3.88) mmHg higher systolic and 1.58 (0.57; 2.58) mmHg higher diastolic trajectories in women with GDM-WHO compared with differences of -0.38 (-1.51; 0.75) and 0.03 (-0.83; 0.89) mmHg in lean women with GDM-WHO. The associations were independent of progression to gestational hypertension. Blood pressure trajectories in pregnancy were elevated across insulin and HOMA-IR quartiles.

Conclusions: GDM-WHO was associated with moderate elevations of blood pressure troughout pregnancy. The relationships were independent of progression to overt gestational hypertension, but largely modified by overweight status.