Comparison of SUZI and ICSI for severe male factor

We compare the results of subzonal insemination (SUZI) and intracytoplasmic sperm injection (ICSI) carried out between February 1993 and end of August 1994. A total of 232 couples underwent 302 cycles of micro-assisted fertilization (79 patients had SUZI for a total of 93 cycles, 153 patients ICSI for a total of 209 cycles). The indications for treatment were obstructive azoospermia in 35 cycles, ejaculatory failure with severely low sperm count in 7 cycles, and failure of fertilization in a previous IVF cycle or less than 10% of oocytes fertilized in 87 cycles. In 173 cycles the indication for treatment was a poor semen parameter. Patients undergoing ICSI had significantly higher fertilization rates [43 (728/1692) versus 22.3% (151/676), chi(2) = 86.308, P < 0.0001], better chances of embryo transfer [95 (199/209) versus 73% (68/93), chi(2) = 30.671, P < 0.001], and greater numbers of embryos transferred (2.4 +/- 0.9 versus 1.6 +/- 1.2 F = 42, P < 0.0001) than patients who had SUZI. Eighteen patients became pregnant following the SUZI procedure, a pregnancy rate of 19% per egg collection, compared with 28% for those who underwent the ICSI procedure, where 58 out of 209 became pregnant. The pregnancy rate was similar in those who underwent embryo transfer, whether they had ICSI or SUZI (29.2 and 28.6% respectively). Overall, the pregnancy rate doubled with each number of embryos transferred, so it was 8.9% when one embryo was transferred, which increased to 18.3% when two embryos were transferred, and this rose to 37.7% when three embryos were transferred. There was no significant difference in the pregnancy wastage rate between SUZI and ICSI. None of the offspring from either SUZI or ICSI showed any evidence of fetal abnormalities. Pregnancy rate was negatively correlated, with sperm progression being 36% (36/100) if progression was <2 and 19.8% (40/202) if it was greater than or equal to 2 (chi(2) = 8.99, p < 0.002). ICSI therefore provides a higher number of embryos available for transfer and should be the primary treatment for severe male factor infertility.