Endometrial evaluation by aspiration biopsy on the day of oocyte retrieval in the embryo transfer cycles in patients with serum progesterone rise during the follicular phase.

OBJECTIVE: To investigate the effect of subtle serum P rise before hCG administration on endometrial maturation in stimulated cycles.DESIGN: Case-control study.SETTING: Tertiary referral center.PATIENT(S): Twenty patients with serum P < or = 0.9 ng/mL (group I) (conversion to SI unit, 3.180), 20 patients with premature P rise (> or = 1.1 ng/mL, group II), and 20 patients with normal serum P (group III).INTERVENTION(S): Patients in groups I and II underwent endometrial aspiration biopsies on the day of oocyte retrieval in the ET cycles themselves. Patients in group III, without endometrial biopsies, were chosen as controls.MAIN OUTCOME MEASURE(S): Comparison of endometrial maturation, correlation between endometrial dating and cumulative P exposure, and/or number of days of P > or = 1.1 ng/mL and comparison of clinical outcome.RESULT(S): Groups I and II showed a secretory activity of the endometrium. In group II, the endometrial dating correlated neither with P exposure nor with the number of days of subtle P rise. Clinical pregnancies were observed in both groups but none in cases with endometrium advanced > 3 days. Similar pregnancy and implantation rates were observed between groups I and III.CONCLUSION(S): These data suggest that an endometrial aspiration biopsy performed on the day of oocyte retrieval may be used to assess endometrial receptivity in patients with serum P rise.