Ultrasound studies of vascular and morphological changes in the human corpus luteum during the menstrual cycle

Objective: To determine changes in corpus luteum (CL) volume, echogenicity, vascularity, and P production relative to a positive test result for urinary LH and day 1 of next menses. Subjects: Thirteen healthy Volunteers (age 23 to 32 years). Interventions: All women underwent transvaginal ultrasonography on cycle day 11 and a urinary LH self-test was used daily. The plan was to rescan all women immediately after a positive test result and then at least every 48 hours (until day 6 of the next cycle); samples of peripheral blood were taken for analysis. Main Outcome Measures: The times of follicular rupture, a positive urinary LH test, and the start of menses; CL volume and echogenicity, maximum peak systolic velocity and minimum impedance, the circulating levels of serum P, E(2), LH, and FSH. Results: Nine women fulfilled criteria for an ovulatory cycle. There was a good correlation between peak systolic velocity, CL volume, and the concentration of serum P from day 4 to 10 after a positive LH test. Peak systolic velocity reached a maximum value between days 7 and 9 relative to a positive urinary LH test and started to decline from day 1 of menses minus 3, 4 days. Conclusion: Changes in peak systolic velocity from the time of a positive urinary LH self-test might be a useful adjunct for monitoring CL function.