Endometrial thickness is a valid monitoring parameter in cycles of ovulation induction with menotropins alone

Objective: To evaluate the ability of an ultrasound (US)-measured periovulatory endometrial thickness to predict conception in hMG-stimulated cycles. Design: Retrospective. Setting: A university-based tertiary practice. Patients: One hundred twelve patients undergoing 292 cycles of ovulation induction with hMG alone. Main Outcome Measures: A periovulatory transvaginal US measurement of endometrial thickness was obtained during cycles of ovulation induction with hMG alone. Clinical pregnancy was defined by fetal cardiac activity. Sensitivity and false-positive rates for multiple discriminatory values of endometrial thickness were calculated and a relative operating characteristic (ROC) curve was constructed to evaluate the performance of this test as a predictor of pregnancy. Results: Thirty-eight of 292 cycles resulted in pregnancy. Conception and nonconception cycles showed similar demographics, diagnoses, peak E₂, maximum number of follicles, midluteal P, and mean endometrial thickness. Ovulatory dysfunction was a more frequent diagnosis in the conception group. Relative operating characteristic analysis for endometrial thickness as a predictor of pregnancy yielded an area under the curve of 0.623 ± 0.049 (mean ± SD). Conclusion: Endometrial thickness is a valid screening test for conception outcome in cycles stimulated with hMG. A periovulatory endometrial thickness ≥ 10 mm defined 91% of conception cycles. No pregnancy occurred when the endometrium measured <7 mm.