MICRO-ASSISTED FERTILIZATION IN PATIENTS WHO HAVE FAILED SUBZONAL INSEMINATION

During the past 3 years we have used direct injection of spermatozoa i nto the cytoplasm of the oocyte (DISCO) in an attempt to procure conce ption in vitro where subzonal insemination (SUZI) has failed. Acknowle dging the paucity of information about this invasive procedure in huma ns, it was clearly the only alternative for some patients. A total of 58 patients (cycles) who had had previously failed SUZI elected for th is approach. Sibling oocytes, where possible, were used as a compariso n between DISCO, SUZI, partial zona dissection (PZD) and microdrop in- vitro fertilization (IVF). Fertilization and embryo transfer was achie ved by 66% (n = 38) of patients. Patients with embryos derived solely from DISCO (n = 19) produced four clinical pregnancies (21%), four pat ients had embryo transfer from SUZI embryos only with no pregnancies, and 15 had embryo transfer from a mixture of SUZI and DISCO embryos, w ith one dizygotic twin pregnancy from a combined SUZI and DISCO embryo transfer (7%). Twins, one male and one female, have been delivered, t here has been one miscarriage and two pregnancies are ongoing. Of the 627 oocytes, 251 were used for DISCO and 71 (28%) were fertilized, 296 were used for SUZI and 29 (10%) were fertilized; 70 were used for PZD , two (3%) were fertilized, and none of the 10 undergoing microdrop IV F were fertilized. Of the 58 patients (cycles) 31% (n = 19) had fertil ization with DISCO only, 8% (n = 4) with SUZI only, 28% (n = 15) with both SUZI and DISCO, while only one (2%) had fertilization with PZD. T he incidence of fertilization in samples with <5% normal forms was hig her (37%) after DISCO than SUZI (15%). Of four cases with globozoosper mia one achieved fertilization with DISCO only, and of eight cases of 100% immotile spermatozoa, two achieved fertilization with DISCO only, and one with SUZI and DISCO. We conclude from this series of patients that DISCO may not only be an advantage when SUZI fails but may becom e the first micro-assisted fertilization approach.