Relationships between pregnancy rates following in vitro fertilization or intracytoplasmic sperm injection and endometrial thickness and pattern.

Objective: To investigate the role of endometrial thickness and pattern on the day of human chorionic gonadotropin (hCG) administration on in vitro fertilization (IVF)/intracytoplasmic injection (ICSI) outcome.

Study Design: A total of 150 infertile women undergoing embryo transfer after IVF/ICSI cycles were studied in a prospective survey. Sonographic features of the endometrium (thickness and pattern) on the day of hCG administration, hormonal profile (progesterone, estradiol, FSH, LH) and various other variables (maternal age, causes and duration of infertility, duration of treatment, number of human menopausal gonadotropin (hMG) ampoules administered, and number of oocytes retrieved) were evaluated. These variables in pregnant and nonpregnant patients were compared.

Results: There was no difference between pregnant and nonpregnant patients in mean endometrium thickness (10.1+/-1 versus 10.2+/-2, p=0.79). Pregnancies occurred only in patients with an endometrial thickness of 9-12 mm (p=0.036). Duration of treatment, number of hMG ampoules administered, number of oocytes retrieved, estradiol concentration, and estradiol/progesterone ratio on the day of hCG differed significantly between pregnant and nonpregnant patients. There was no correlation between endometrial pattern and pregnancy rate. The receiver-operating characteristic (ROC) curve and multiple logistic regression showed no significant effect of endometrial thickness in the outcome of IVF/ICSI.

Conclusion: The sonographic features of the endometrium (thickness and pattern) on the day of hCG administration did not differ between pregnant and nonpregnant patients. The pregnancy rate declined beyond two limits of endometrial thickness.