Effect of incremental time experience on the results of in vitro fertilization with intracytoplasmic sperm injection (ICSI)

Our objective was to determine the effect of experience on the results with intracytoplasmic sperm injection. The quarterly outcome with both ICSI and traditional in vitro fertilization (IVF) in 1994 was analyzed in 475 patients under age 40 undergoing 595 oocyte retrievals. The data represent 307 patients undergoing 379 retrievals for IVF and 165 patients undergoing 216 retrievals for ICSI. Fertilization rates with ICSI improved significantly each quarter (52.96, 62.17, 70.17, and 74.87% in Q-I, Q-II, Q-III, and Q-IV, respectively), while the rate with IVF improved significantly between Q-I (69.9%) and Q-II (80.10%) and slightly but significantly between Q-II and Q-IV (82.88%). The implantation rate per embryo after ICSI improved significantly after Q-I (6.17%) compared to Q-II (10.70%) and Q-IV (12.14%). The pregnancy rate per transfer with ICSI increased steadily after Q-I (13.79, 21.88, 23.53, and 25.00% in Q-I through Q-IV), reaching statistical significance between Q-I and Q-III and between Q-I and Q-IV. Although acceptable results can be obtained with ICSI after a relatively short period of time, optimum results require substantial experience.