Pulse pressure and risk of preeclampsia: a prospective study.

OBJECTIVE: To find whether pulse pressure, a measure of arterial compliance, is associated early in pregnancy with increased risk of developing preeclampsia.
METHODS: In a prospective cohort of 576 nulliparas, we examined blood pressures throughout pregnancy and at 6-8 weeks postpartum. Measurements during weeks 7-15, 16-24, and 25-38 of gestation were pooled to find averages for each period. Outcomes assessed were gestational hypertension and preeclampsia. Logistic regression analysis was used to develop relative risks and 95% confidence intervals.
RESULTS: We confirmed 34 (5.9%) cases of preeclampsia, 32 (5.6%) cases of gestational hypertension, and 510 normotensive women. Mean systolic and diastolic blood pressures and mean arterial pressures were elevated throughout pregnancy in women who developed hypertensive disorders of pregnancy compared with normotensive women. Pulse pressure at 7-15 weeks was significantly higher in women who developed preeclampsia (45 +/- 6 mmHg) than in those who developed gestational hypertension (41 +/- 7 mmHg, P =.03) and normotensive women (41 +/- 8 mmHg, P =.01). Examined in tertiles, increasing pulse pressure was associated with increasing risk of developing preeclampsia (P for trend =.01) but not gestational hypertension (P for trend =.95). After adjustment for potential confounders, a 1-mmHg rise in early pregnancy pulse pressure was associated with a 6% (95% confidence interval: 1, 10) increase in risk for developing preeclampsia but not gestational hypertension (relative risk: 1%; 95% confidence interval: -1, 6). Beyond 15 weeks' gestation, differences between groups diminished, but women with any hypertensive disorder had higher pulse pressures than women with uncomplicated pregnancies.
CONCLUSION: Elevated pulse pressure, indicating poor arterial compliance, was evident early in pregnancies of women who subsequently developed preeclampsia.