[Intracytoplasmic injection of morphologically selected spermatozoa from patients with male factor infertility: clinical and embryo development outcomes].

Objective: To test whether intracytoplasmic injection of morphologically selected spermatozoa (IMSI) from patients with male factor infertility can improve the clinical and embryo development outcomes of intracytoplasmic sperm injection-embryo transfer (ICSI-ET).

Methods: We performed IMSI for 82 couples diagnosed with obstructive azoospermia at high magnification (×6600) and traditional ICSI for another 91 couples using testicular sperms. We also performed IMSI for 44 couples with teratozoospermia at high magnification (×6600) and traditional ICSI for 71 patients using ejaculated sperms. The clinical and embryo development outcomes were compared between the cycles.

Results: For obstructive azoospermia, IMSI and ICSI showed no significant difference in the rates of cleavage (95.5% vs 96.7%), D3 top quality embryos (28.2% vs 29.2%), implantation (26.4% vs 32.3%), pregnancy (47.3% vs 50%), blastocyst formation (54.3% vs 54.6%), or abortion (14% vs 7.3%) (P>0.05), but a significantly higher normal fertilization rate was achieved in IMSI group (84.3% vs 77%, P<0.05). For teratozoospermia, the 2 techniques resulted in no significant differences in the rates of cleavage (96.2% vs 95.2%), D3 top quality embryo (27.6% vs 27.1%), implantation (28.2% vs 30.7%), pregnancy (43.7% vs 43.2%), or abortion (9.7% vs 10.5%) (P>0.05), but the normal fertilization rate (68% vs 75.5%) and the blastocyst formation rate (54.6% vs 67.9% ) were significantly higher in IMSI group (P<0.05).

Conclusion: IMSI can improve the normal fertilization rates in couples with male factor infertility (including obstructive azoospermia and teratozoospermia) and increase blastocyst formation rate in cases of azoospermia.