Endometrial perfusion across the normal human menstrual cycle assessed by laser Doppler fluxmetry

This study investigated variations in microvascular perfusion of humanendometrium across the menstrual cycle, using a laser Doppler technique toassess red blood cell (RBC) flux. Endometrial RBC flux was monitored bylaser Doppler fluxmetry via a fibre optic probe inserted transvaginallyinto the uteri of 19 conscious normal volunteer women, on four occasions atweekly intervals over one menstrual cycle. Regional variation in RBC fluxwas investigated in 16 surgical patients under general anaesthesia and infive excised uteri. Endometrial perfusion exhibited short-term temporalvariations consistent with the cardiac cycle and often also showedvasomotion (5-12 cycles/min). Mean endometrial perfusion differed betweenphases of the menstrual cycle in conscious women, being highest duringearly proliferative and early follicular phases. There were no significantregional differences in local mean endometrial perfusion in anaesthetizedpatients. No evidence of endometrial ischaemia/reperfusion episodes wasfound in any subject using this technique. This study provides benchmarkdata of variations in RBC flux per unit volume of tissue in the luminalapproximately 1 mm of endometrium, across the normal human menstrual cycle.Flux values were highest at times associated with endometrial growth andpreparation for implantation, indicating that RBC flux may be a usefulparameter for assessment of endometrial physiology.