Muscle sympathetic nerve activity peaks in the first trimester in healthy pregnancy: a longitudinal case study

作者：Hissen Sarah L; El Sayed Khadigeh; Macefield Vaughan G; Brown Rachael; Taylor Chloe E^*

来源：Clinical Autonomic Research, 2017, 27(6): 401-406.

DOI：10.1007/s10286-017-0439-1

• Pregnancy
• Blood pressure
• Baroreflex sensitivity
• Microneurography

Muscle sympathetic nerve activity and baroreflex sensitivity were examined at rest before, during (weeks 6, 11, 17, 22, 25, 33 and 36) and after a normotensive pregnancy.
Muscle sympathetic nerve activity is elevated during pregnancy with a large peak in the first trimester (Delta 17 bursts/min) and a secondary peak in the third trimester (Delta 11 bursts/min). Cardiac baroreflex sensitivity peaked in the first trimester (10 vs. 6 ms/mmHg pre-pregnancy), whereas sympathetic baroreflex sensitivity was greater throughout.
The increase in sympathetic outflow early in pregnancy cannot be explained by a reduction in baroreflex sensitivity, while the secondary increase in burst frequency in the third trimester may, in part, be explained by the elevated heart rate.

• 出版日期2017-12