Changes in haemodynamic and autonomous nervous system parameters measured non-invasively throughout normal pregnancy.

OBJECTIVE

To examine non-invasively haemodynamic and autonomous parameters throughout normal pregnancy.

STUDY DESIGN

We used the Task Force Monitor 3040i system to retrieve, record, and calculate haemodynamic as well as autonomous parameters. 20 healthy women were included and scheduled for longitudinal examinations throughout normal pregnancy. Heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (CO), systemic vascular resistance (SVR), heart rate variability (HRV), blood pressure variability (BPV), and baroreceptor sensitivity (BRS) were measured. Measurements were performed at gestational week 10(+0)-13(+6), 15(+0)-18(+6), 20(+0)-22(+6), and >30(+0).

RESULTS

HR increased during gestation showing a significant increase at III versus I trimester (74 bpm vs. 88 bpm, P<.05). Mean arterial pressure remained stable until III trimester, when a significant increase compared to I trimester could be noted (78 mm Hg vs. 86 mm Hg, P<.05). SV and CO remained relatively stable in I and II trimester, and in III trimester significant decreases were observed. In contrast, SVR increased significantly at III trimester (P<.001). Whereas HRV and BPV did not change at different gestational ages, BRS was significantly lower in III trimester compared to I trimester values (P<.05).

CONCLUSION

The non-invasive determination of cardiovascular and autonomous parameters throughout pregnancy is possible and the results of this pilot study can serve as basic parameters for classifying and assessing cardiovascular and autonomous changes in pathological conditions in pregnancy such as hypertensive disorders.