A prospective controlled study of luteal and endometrial abnormalities in an infertile population

Objective: To investigate whether luteal and endometrial abnormalities occur more frequently in an infertile population and thus contribute to infertility. Design: Prospective controlled clinical study. Setting: Outpatient clinic in an academic research institution. Participants: Thirty- three fertile controls and 31 infertile women without ovulatory disorders, tubal disease, or male factors. Interventions: All women underwent an endometrial biopsy 9 days after the LH surge followed by an IM injection of 5,000 IU hCG. Blood samples were drawn immediately before hCG administration for serum P and placental protein 14 (PP14) measurements, at 6 hours after hCG stimulation for serum P concentrations, and on day 5 after hCG administration for serum PP14 levels. Main Outcome Measures: Histologic dating of the endometrium and serum P and PP14 measurements. Results: Abnormal endometrial biopsies occurred more frequently in infertile (43%) than in fertile women (9%). Except for one case, these specimens were not associated with low hCG-stimulated P levels. Serum PP14 measurements varied widely and did not discriminate subjects with abnormal endometrial development. Conclusions: Disruption of endometrial maturation without a concomitant defect of the corpus luteum occurs more frequently in an infertile population and thus may contribute to infertility.