Survey on intracytoplasmic sperm injection: report from the ESHRE ICSI Task Force. European Society of Human Reproduction and Embryology.

Intracytoplasmic sperm injection (ICSI) has revolutionized the treatment of male infertility, since normal fertilization and ongoing pregnancies can be achieved with severely affected spermatozoa. Hence, the application of ICSI is rapidly expanding around the world, necessitating an accurate assessment of the efficacy and safety of this novel technique. The European Society of Human Reproduction and Embryology (ESHRE) Task Force is gathering data annually on the clinical results, the pregnancy outcome and the follow-up of children born after ICSI using ejaculated, epididymal and testicular spermatozoa, in order to be able to provide reliable information on these important issues. During the 3 years 1993-1995, the number of centres performing ICSI increased from 35 to 101, and the total number of ICSI cycles performed per year rose from 3157 to 23932. The incidence of oocytes damaged by the procedure remained low (<10%) and the fertilization rates obtained with ejaculated, epididymal and testicular spermatozoa in 1995 were 64, 62.5 and 52% respectively. Thus, approximately 90% of the couples had an embryo transfer and the viable pregnancy rate was 21% for ejaculated, 22% for epididymal and 19% for testicular spermatozoa (with 25-30% multiple pregnancies). Furthermore, 3149 transfers of frozen-thawed embryos were performed and 7-11% of them resulted in a viable pregnancy. The ICSI results were similar during this 3 year period, irrespective of the origin of the spermatozoa. The perinatal outcome of children born after ICSI was not different from those born after in-vitro fertilization (IVF) or natural conception, and was only affected by multiplicity. Moreover, the incidence of major or minor malformations was not increased, but the chromosomal, especially the sex-chromosomal, aberration rate was slightly elevated. To summarize, a very high success rate is obtained by ICSI independently of the source of the spermatozoa, verifying the superiority of ICSI over conventional IVF. The procedure seems to be safe, but further follow-up of the children is necessary in order to be able to assess its safety more accurately.