Three protocols for monitoring follicle development in 587 unstimulated cycles of in vitro fertilization and intracytoplasmic sperm injection. A comparison.

To test the adequacy of unstimulated cycles for intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) and to evaluate implantation and pregnancy rates in three monitoring protocols.A retrospective chart review of 587 patients undergoing IVF and ICSI in unstimulated cycles was performed. In the first group (protocol A), all cycles were monitored by ultrasound only. Human chorionic gonadotropin (hCG) was given when the mean follicle diameter reached 18 mm. In protocol B, hCG was given when serum estradiol (E2) or follicle diameter reached the critical value (0.91 nmol/L and 18 mm). With a smaller follicle diameter, the E2 level had to be higher, and vice versa. In protocol C, hCG was administered when the serum E2 was > 0.49 nmol/L and follicle diameter at least 15 mm. Cycles with positive luteinizing hormone in urine before hCG was given were cancelled.The cancellation rate was lower in protocol C (33/335, 9.8%) than protocol B (42/151, 27.8%) and A (41/101, 40.5%). In protocol C the pregnancy rate per cycle was higher with IVF (n = 219) and ICSI (n = 116) cycles (10.5% and 12.1%) than when protocol B was used (3.8% and 4.3%). The pregnancy rate per transfer was highest when protocol C was used in the IVF (23/105, 21.9%) and ICSI group (14/53, 26.4%).Unstimulated cycles monitored by serum E2, urinary luteinizing hormone and ultrasound can produce an acceptable pregnancy rate after IVF and ICSI.