Higher success rate by intracytoplasmic sperm injection than by subzonal insemination. Report of a second series of 300 consecutive treatment cycles.

Subzonal insemination (SUZI) and intracytoplasmic sperm injection (ICSI) were carried out in 300 treatment cycles in couples unable to be helped by conventional in-vitro fertilization treatment. More oocytes were damaged by ICSI (13.5%) than by SUZI (7.1%). The normal fertilization rate was substantially higher after ICSI (51.0%) than after SUZI (14.3%) and was related to the semen characteristics. The cleavage rate was similar for both procedures (77%). After 217 embryo transfers (72.3% of the treatment cycles) 66 pregnancies were established, i.e. pregnancy rates of 22.0% per started cycle and 30.4% per embryo transfer. So far, pregnancy loss has occurred in 27.3% of the pregnancies, nine healthy children have been born after eight deliveries and 41 clinical pregnancies are progressing uneventfully. Chorionic villus sampling or amniocentesis have been performed in 35 pregnancies and 39 normal fetal karyotypes have been obtained after cytogenetic analysis.