Abstract 19083: Onset of Preeclampsia is Preceded by Significant Structural Capillary Rarefaction
The microcirculation plays an important role in the pathogenesis of essential hypertension (EH) and preeclampsia (PE). Microvascular rarefaction defined as reduced vascular spatial density is a consistent finding in hypertension. Functional and structural capillary rarefaction (CR) occurs in individuals with sustained and borderline EH and also in their normotensive offspring. We hypothesised that CR precedes the development of preeclampsia (PE) and could play a role in its pathogenesis.
Methods: We recruited 322 Caucasian women, of which 305 subjects completed the study and were included in the analysis. We used intravital video-microscopy to measure basal i.e. functional (BCD) and maximal i.e. structural (MCD) capillary densities in the skin of the dorsum of fingers according to a well-validated protocol. Subjects were studied at 5 visits; 11–16, 20–25, 27–32, 34–38 weeks and 5–15 weeks postpartum.
Results: At the end of pregnancy 272 women had normal pregnancy (mean age 32.2±4.0 yrs, BMI 24.0±4.2 Kg/m2, BP 106/62±9/8 mmHg) and 16 women (mean age 32.4±3.1 yrs, BMI 25.8±5.1, BP 113/68±12/11 mmHg) developed PE (mean onset at 35.6±4.8 weeks; range 27.0–41.5 weeks). Seventeen women had either developed hypertension, or their pregnancy was complicated by intrauterine growth retardation. In women who developed PE, MCD showed significant secondary rarefaction at 20–25 weeks (mean difference of −6 capillaries/field compared to baseline visit, p=0.001). Further rarefaction occurred at 27–32 weeks (mean difference of −11 capillaries/field, p=0.0001) and 34–38 weeks (mean difference of −13 capillaries/field, p=0.001). Compared with normal pregnancy significant MCD rarefaction (but not BCD) was observed at 27–32 weeks and persisted till the post-partum period.
Conclusions: To our knowledge this is the first study to show that significant structural capillary rarefaction precedes the onset of PE. Our results indicate that capillary rarefaction could play a role in the pathogenesis of this disease.
- © 2010 by American Heart Association, Inc.