Obesity and preeclampsia: the potential role of inflammation.

OBJECTIVE: Systemic inflammation might contribute to the pathogenesis of preeclampsia. In addition, the association between obesity and inflammation in preeclampsia has not been examined in detail. We determined whether first-trimester elevation of serum C-reactive protein, an index of systemic inflammation, was associated with preeclampsia. METHODS: We conducted a prospective, nested case-control study among women enrolled in the Massachusetts General Hospital Obstetrical Maternal Study cohort. High-resolution C-reactive protein assays were performed on first-trimester (11 +/- 2 weeks' gestation) serum samples in 40 women in whom preeclampsia developed (blood pressure [BP] greater than 140/90 mmHg, and proteinuria, either 2+ or more by dipstick or greater than 300 mg per 24 hours), and in 80 matched controls. This sample size had greater than 80% power to detect a difference in C-reactive protein levels between cases and controls. We used nonparametric tests to compare C-reactive protein levels and conditional logistic regression to control for confounding variables. RESULTS: First-trimester C-reactive protein levels were significantly higher among women in whom preeclampsia subsequently developed compared with controls (4.6 compared with 2.3 mg/L, P =.04). When women were subdivided into C-reactive protein quartiles, the odds ratio (OR) of being in the highest quartile of C-reactive protein was 3.2 (95% confidence interval [CI] 1.1, 9.3, P =.02) among cases of preeclampsia compared with controls. When body mass index (BMI) was added to the multivariable model, the highest quartile of C-reactive protein was no longer associated with increased risk of preeclampsia (OR 1.1, 95% CI.3, 4.3, P =.94). In the same model without BMI, the highest quartile of C-reactive protein was associated with increased risk of preeclampsia (OR 3.5, 95% CI 1.3, 9.5, P =.01). CONCLUSION: In women with preeclampsia, there was evidence of increased systemic inflammation in the first trimester. Inflammation might be part of a causal pathway through which obesity predisposes to preeclampsia.

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.