We monitored blood pressure (BP) for a 24-h period in type 1 diabetic women at each trimester of pregnancy (10-13, 20-22, and 30-33 weeks of gestation) to identify early alterations of BP profile in pregnancies complicated by hypertension.
Patients and methods: We prospectively studied 71 type 1 diabetic pregnant women and 48 nondiabetic pregnant women (homogeneous by age and pre-pregnancy BMI) consecutively recruited at 10+/-2 weeks of pregnancy in the space of 2 years (1999-2000). They were all normotensive (<130/80 mm Hg) and normoalbuminuric (AER<20 microg/min) at entry to the study.
Statistics: Analysis of variance (ANOVA) and simple regression and chi(2) were applied as appropriate by an Apple software program (Stat View).
Results: In diabetic women, we recorded higher levels of diastolic BP (even if within a normal range) at each time point; diabetic vs. nondiabetic women: first trim daytime diastolic BP: 71.35+/-8.75 vs. 67.7+/-9.7, P=.01; second trim nighttime diastolic BP: 62.15+/-6.45 vs. 58.05+/-6.7, P=.05; third trim nighttime diastolic BP: 66.03+/-8.72 vs. 60.7+/-6.5, P=.01. Among diabetics, those who later developed pregnancy-induced hypertension (36.6%) showed significantly higher values of BP at the first and third trimester compared to those who remained normotensive. In the two groups, there were no differences in age and pre-pregnancy BMI by contrast of diabetes duration (hypertensive vs. normotensive, 19.18+/-7.3 vs. 14.35+/-9.1 years, P=.03) and age of diagnosis (hypertensive vs. normotensive, 9.6+/-5.5 vs. 14.7+/-8.6 years, P=.01). Positive correlation was found between fasting blood glucose and diastolic BP at each trimester of pregnancy.