Blood Pressure Changes During the Normal Menstrual Cycle in Adolescent Females

Study Objective: The objective of this study was to investigate blood pressure (BP) changes during the menstrual cycle in adolescents. Methods: Prospective primary data collection study. Systolic (SBP) and diastolic (DBP) pressures were measured from 22 female and 5 control male adolescents, daily for eight weeks. Readings taken on and after the onset of the first menstruation contributed to the primary analysis. Readings taken before this, in their previous cycle, were used to investigate consistency in trends observed in the primary analysis. BP was compared between different phases of the cycle. Results: The primary analysis revealed that adjusted SBP was non-significantly higher in the luteal phase than follicular by 0.61mmHg (95%CI: -1.29to3.51; P=0.53). There was no statistical difference in DBP between the phases -0.07 (-1.62to1.48; P=0.93). In the previous cycle, however, SBP and DBP were higher during the follicular phase than the luteal (P=0.02 for both). This finding may be due to greater stress response, as these measurements were taken earlier in the experiment. Stress response is likely to affect the follicular phase more, as it is the first phase. This phenomenon was also observed in the male controls. Conclusions: BP does not change during the menstrual cycle in adolescents. This has potential clinical implications. Physicians cannot attribute BP variations in adolescent females to their menstrual cycle and therefore may warrant further investigation. Another finding is that researchers investigating BP should consider a long familiarization period, between subjects and the experimental environment, to minimize stress response.