PP111. The preceding features before onset of gestational hypertension and preeclampsia in home blood pressure monitoring: The existence of the inflection point and the rapid increased speed of blood pressure.

INTRODUCTION

It has not been clarified whether home blood pressure monitoring (HBPM) during pregnancy is useful to detect high risk pregnant women with later onset of gestational hypertension (GH) and preeclampsia (PE).

OBJECTIVES

We thought to determine the preceding features of blood pressure (BP) in HBPM before the onset of GH and PE. We especially focused on the existence of the inflection point, its level, when it occurs, and the increased speed of BP after the inflection point. We compared these features in normal pregnant women (NP), women with GH, and women with PE.

METHODS

In this prospective cohort study, 361 singleton pregnant women, among them 100 women recruited due to high risk for GH/PH in the second trimester, participated in a couple of tertiary perinatal centers between 2008 and 2010. HBPM were measured with the validated OMRON HEM-5001(R) automated digital oscillometric sphygmomanometer (OMRON Healthcare Japan). The device was programmed to take three consecutive readings at 15-second interval. HBPM was measured twice a day, at the time of awakening and sleep, through the first to third trimester, and the average systolic blood pressure (SBP) and diastolic blood pressure (DBP) of each gestational week (almost 42 times a week) were calculated. We defined the data of HBPM which started before 28 gestational weeks and continued until 2 weeks before the onset of GH/PE or delivery are eligible. The increased speed of systolic or diastolic BP after the inflection point was defined as ("BP at the onset in GH/PE or at delivery in NP" - "BP at the inflection point") / ("Gestational weeks at the onset in GH/PE or at delivery in NP" - "Gestational weeks at the inflection point"). If there was no inflection point in HBPM, the increased speed of BP was defined as zero. The comparisons were performed using one-way analysis of variance (ANOVA) followed by multiple comparison. Data were shown as mean±SE.

RESULTS

A total of 17 (4.7%) women developed PE, and 12 (3.3%) GH.The systolic blood pressure (SBP) levels at the inflection point in NP, GH and PE was 102.4±1.3, 118.7±2.9 and 117.4±2.2mmHg, respectively (Significant pairs: NP < GH, PE); the diastolic blood pressure (DBP) levels at the inflection point was 59.2±1.0, 74.5±2.0 and 73.1±2.0mmHg, respectively (NP < GH, PE). The inflection point in NP, GH and PE occurred at 31.3±0.9, 28.4±1.5 and 22.3±1.4weeks, respectively (PE < GH, NP). The increased speed of SBP in NP, GH and PE was 1.2±0.1, 3.0±0.4 and 4.7±0.7mmHg/wk, respectively (NP < GH, PE); the increased speed of DBP was1.1±0.1, 2.1±0.3 and 2.8±0.4mmHg/wk, respectively (NP < GH, PE).

CONCLUSION

In women with later onset of GH/PE, the BP level at the inflection points was higher than in NP. The average inflection point in PE was earlier gestational weeks than in GH and NP. The average increased speed of blood pressure after the inflection point in GH/PE was faster than in NP. The preceding features of BP in HBPM may be clinically useful to detect high risk women with later onset of GH/PE.