Haemorheological changes during the menstrual cycle

Objective: To determine changes in some haemorheological parameters: haematocrit (Hct), Whole Blood Relative Viscosity (WBRV), Erythrocyte Sedimentation Rate (ESR) and Fibrinogen Concentration (FC) during the menstrual cycle. Design: Cross-sectional prospective study. Subjects: Three hundred and fifty randomly selected female undergraduate students of the University of Port Harcourt, Port Harcourt, Nigeria. Setting: Departments of Human Physiology and Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Port Harcourt, Port Harcourt, Nigeria. Main outcome measures: Significant variation (p< 0.05) were found in the values of all four haemorheological parameters assessed in the various phases of the menstrual cycle. Results: Both haematocrit (Hct) and Whole Blood Relative Viscosity (WBRV) showed a similar trend, being highest in the ovulatory phase, followed by the luteal phase and follicular phase, and lowest in the menstrual phase. The Erythrocyte Sedimentation Rate (ESR) however, showed a pattern opposite to both Hct and WBRV, being highest in the menstrual phase followed by the luteal phase, and the follicular phase, and lowest in the ovulatory phase. The Fibrinogen Concentration (FC) was highest in the menstrual phase, followed by the ovulatory phase, the luteal phase and was lowest in the follicular phase. Conclusion: The study shows that significant variation could occur in some haemorheological parameters during the phases of the normal menstrual cycle. (East African Medical Journal: 2002 79(4): 181-183