A patient married for 3 years, unable to conceive, has regular menstrual cyclesHusbands semen analysis is normal and so is his hormonal profile What is the right time in menstrual cycle to do endometrial biopsy for infeility:-

Endometrial biopsy is best done on 21st - 23rd day of the cycle. Evidences of secretory activity of the endometrial glands in the second half of the cycle give not only the diagnosis of ovulation but can predict the functional integrity of the corpus luteum. Luteal Phase Defect- Lag of 2 to 4 days in observed/expected secretory changes. Recognized as cause of infeility.