RESUMO
<p><b>OBJECTIVE</b>To evaluate the clinical outcomes of half intracytoplasmic sperm injection (partial ICSI) treatment in infertile patients with potential fertilization failure.</p><p><b>METHODS</b>A total of 109 partial ICSI cycles of in vitro fertilization-embryo transfer (IVF-ET) were classified into 5 groups, namely group A (infertile patients for unidentified causes, 17 cycles), group B (oligo-asthenozoospermia patients, 28 cycles), group C (teratozoospermia patients, 8 cycles), group D (primary infertile patients without definite causes, 31 cycles), and group E (secondary infertile patients without definite causes, 25 cycles). The fertilization rate and normal fertilization rate after IVF and ICSI were compared between the groups.</p><p><b>RESULTS</b>Significant differences were found in the fertilization rate following conventional IVF and ICSI in group A (53.1-/+38.8% vs 72.2-/+34.1%) and group D (58.8-/+31.6% vs 82.7-/+21.4%) (P<0.05), but not in groups B, C and E (P>0.05). The normal fertilization rates following IVF and ICSI in groups A, B, D, E were statistically different (P<0.05), but similar in group C (P>0.05).</p><p><b>CONCLUSION</b>ICSI treatment may increase the fertilization rate of IVF-ET in patients with unexplained infertility and primary infertility, but not in patients with oligo-asthenozoospermia, teratozoospermia or secondary infertility.</p>