Cardiovascular Autonomic Responses to Head-up Tilt in Gestational Hypertension and Normal Pregnancy

Aims: The aim of the present study was to evaluate the influence of gestational hypertension on hemodynamics and cardiovascular autonomic regulation at rest and their responses to head-up tilt (HUT). We prospectively studied 56 pregnant women (28 with gestational hypertension and 28 healthy pregnant women) during the third trimester of pregnancy and 3 months after pregnancy.

Major Findings: In women with pregnancy-induced hypertension, compared with control women, there were significant differences in hemodynamics and in markers of cardiovascular regulation (p < 0.05 to p < 0.001). Postural change from the supine to the upright position was associated with significant changes in hemodynamic responses in both groups during pregnancy (from p < 0.05 to p < 0.001). Regulatory response to HUT in both groups was characterized with a decrease in HF power and increase in LF/HF ratio (from p < 0.01 to p < 0.001). Responses to HUT in total power and VLF power were attenuated in hypertensive pregnancies (p < 0.001 to p < 0.01, respectively, vs control group).

Conclusions: Our results suggest that autonomic cardiovascular regulation may not play a major role in women with gestational hypertension . The lack of irreversible changes in autonomic nervous function in hypertensive women appeared to be a feature of gestational-induced hypertension.