Objective: To compare function and histologic structure of the corpus luteum (CL) to the morphology of the endometrium and the fallopian tube in normally menstruating women.
Design: Circulating steroid and luteinizing hormone (LH) levels were compared with CL steroid production in vitro and the histology of CL, endometrium, and the fallopian tube at four stages of the postovulatory phase (days LH +/- 0/LH+3, LH+4/LH+7, LH+8/LH+11, LH+12/onset of menstruation). SETTING OF PATIENTS: The study included 28 volunteers with proven fertility undergoing surgical sterilization timed in relation to the LH surge.
Interventions: Blood and urine samples for LH, progesterone (P), and estradiol assessment were obtained before (simultaneously with ultrasound examinations), during, and after operation. Biopsy specimens from CL, endometrium, and fallopian tube were taken at the surgical sterilization and subjected to morphometric analyses.
Main outcome measures and results: Significant correlation was found between the endometrial dating and the LH surge (r = 0.923) and between the dating of the endometrial and CL biopsies (r = 0.918). A significant correlation (P less than 0.01) existed between circulating P levels and two endometrial indices; the number of vacuolated cells (LH+4/LH+7) and the glandular diameter (LH+8/LH+11).
Conclusion: In normally menstruating women, the endometrial biopsy is likely to closely gauge the CL activity provided the biopsy is timed in relation to the LH surge.