Sensitivity of spontaneous baroreflex control of the heart and hemodynamic parameters are not influenced by the menstrual cycle.

OBJECTIVE: The purpose of this study was to evaluate if hemodynamic parameters and sympathetic activity vary between the follicular and luteal phase of the menstrual cycle before using sympathetic activity in pre-pregnancy risk assessment for preeclampsia. METHODS: We studied 39 healthy women at days 5 to 10 and days 18 to 25 of the menstrual cycle. Blood pressure, heart rate, cardiac output, and total peripheral resistance were measured continuously using noninvasive finger arterial pressure waveform registration (Portapres Model 2, BMI, The Netherlands). Baroreflex sensitivity (BRS) and sympathetic activity by phase angle difference were studied using spectral analysis and xBRS. RESULTS: There were no differences in hemodynamic parameters, BRS, and phase angle difference. CONCLUSION: There is no difference in blood pressure, BRS, and sympathetic activity between the first and second half of the menstrual period. We recommend using the first half of the cycle to be certain that no pregnancy exists, as the influence of very early pregnancy is unknown.