Use of urinary luteinizing hormone immunoassays in the assessment of luteal function in infertile women.

It has been suggested that the chronologic date of an endometrial biopsy performed to evaluate luteal adequacy should be based on the date of the luteinizing hormone surge rather than the date of the next menstrual period. Sixty-four infertile women used a urinary luteinizing hormone immunoassay to identify the luteinizing hormone surge; timed serum progesterone level tests and an endometrial biopsy were then performed. An out-of-phase endometrium was identified in 26.6% of cycles dated traditionally and 28.1% of cycles dated from the luteinizing hormone surge. No relationship was identified between progesterone levels and endometrial biopsy results when the next menstrual period was used. When the luteinizing hormone surge was used no progesterone cutoff value could be identified that would reliably distinguish between in-phase and out-of-phase cycles. Use of a urinary luteinizing hormone immunoassay offers no advantage over the next menstrual period and does not lead to better agreement between histologic and chronologic dating.