Comparison of vagal baroreflex function in nonpregnant women and in women with normal pregnancy, preeclampsia, or gestational hypertension

OBJECTIVE: Our aim was to compare baroreflex function among nonpregnant wom en and among women with normal pregnancy, preeclampsia, or gestational hype rtension. STUDY DESIGN: Baroreflex function was tested in 20 women with preeclampsia, in 20 age- and,gestational age-matched normotensive gravid women, in 20 ag e-matched nonpregnant women, and in 20 nonmatched women with gestational hy pertension. The baroreflex was measured by several modalities. RESULTS: Vagal baroreflex gain measured by cross-spectral analysis of paral lel spontaneous heart rate and blood pressure changes is significantly decr eased in normal pregnancy (15.8 +/- 7.2 vs 10.8 +/- 4.1 ms/mm Hg; P = 0.001 ), in comparison with vagal baroreflex gain in nonpregnant women. Barorefle x gain is further reduced in preeclamptic pregnancy (10.8 +/- 4.1 vs 7.2 +/ - 2.6 ms/mm Hg; P = 0.003) and in gestational hypertension (10.8 +/- 4.1 vs 6.5 +/- 2.7 ms/mm Hg; P = 0.001), compared with that in normal pregnancy. Similar differences were seen with other baroreflex testing modalities. CONCLUSIONS: The normal reduction of baroreflex gain in pregnancy is furthe r depressed in subjects with hypertensive disorders of pregnancy.