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 women and among women with normal pregnancy, preeclampsia, or gestational hypertension. Study Design: Baroreflex function was tested in 20 women with preeclampsia, in 20 age- and gestational age–matched normotensive gravid women, in 20 age-matched nonpregnant women, and in 20 nonmatched women with gestational hypertension. The baroreflex was measured by several modalities. Results: Vagal baroreflex gain measured by cross-spectral analysis of parallel spontaneous heart rate and blood pressure changes is significantly decreased 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. Baroreflex 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 further depressed in subjects with hypertensive disorders of pregnancy. (Am J Obstet Gynecol 2001;184:1189-95.)