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Sympathetic Neural Activity During Early Pregnancy in Women with Prior Gestational Hypertension and Preeclampsia
Author(s) -
Stickford Abigail,
Best Stuart,
Parker Rosemary,
Roberts Monique,
Levine Benjamin,
Fu Qi
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.830.6
Subject(s) - preeclampsia , gestational hypertension , medicine , obstetrics , pregnancy , biology , genetics
Background Sympathetic overactivity likely plays a role in the primary manifestation of gestational hypertension and preeclampsia, and may contribute to the substantially‐elevated risk for recurrence in women with a history of the disorders. We tested the hypothesis that women with a history of hypertensive pregnancy would have augmented neural activity prior to and during the early phase of a subsequent pregnancy. Methods: Healthy women with (HP+; n= 8) and without (CON; n = 8) a history of hypertensive pregnancy were tested prior to (PRE, mid‐luteal phase) and during EARLY (4‐8 weeks) pregnancy. Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, and muscle sympathetic nerve activity (MSNA) were measured during 6 min of supine rest, followed by 6 min of 60° head‐up tilt (HUT). Results: There were no group differences in supine or HUT HR, SBP, or DBP at either PRE or EARLY. Supine and HUT MSNA tended to be higher in HP+ compared to CON during PRE (p = 0.098). During EARLY, supine MSNA increased from PRE in both groups (p < 0.001) and tended to be greater in HP+ than CON (28 ± 9 vs. 20 ± 9 bursts·min ‐1 ; p = 0.11); however, HP+ women had an attenuated increase in MSNA from supine to HUT (ΔMSNA: 15 ± 7 vs. 26 ± 9 bursts·min ‐1 ; p = 0.014). Conclusions Despite similar hemodynamic responses, HP+ women appear to have elevated MSNA at rest but attenuated sympathetic responses to upright tilt during early pregnancy, compared to healthy women. A “ceiling” effect (a reduced sympathetic reserve during tilting) and/or decreased sympathetic baroreflex sensitivity may be the underlying mechanism(s).