Negli ultimi anni è stato dato molto risalto ad una tecnica di selezione degli spermatozoi chiamata IMSI. Alcuni gruppi hanno riscontrato un vantaggio di questa tecnica per la selezione dello spematozoo da utilizzare per la ICSI rispetto alla microscopia ottica tradizionale.

Un recente studio condotto su un ampio numero di ovociti ha dimostrato simili percentuali di fertilizzazione e di formazione di embrioni top-quality negli ovociti inseminati con la ICSI classica e in quelli inseminati con spermatozoi selezionati con la IMSI.

Allo stato attuale delle conoscenze, non è dimostrato un vantaggio clinico della IMSI rispetto alla selezione degl ispermatozoi effettuata con microscopia ottica tradizionale. Non sembra quindi giustificata l'introduzione di routine di questa procedura nella pratica clinica.

Di seguito la referenza completa

IMSI produces similar top-quality embryos to ICSI
Week 17 - 26 Apr 2010

Source: European Journal of Obstetrics and Gynecology and Reproductive Biology 2010; Advance online publication

Investigating whether intracytoplasmic morphologically selected sperm injection influences early paternal effects by observing embryo quality at day 2.

MedWire News: Intracytoplasmic morphologically selected sperm injection (IMSI) produces embryos of the same quality as intracytoplasmic sperm injection (ICSI), show study results.

No differences were observed in fertilization rate, early embryo cleavage or cleavage rates on day 2, and both methods produced similar numbers of top quality embryos (four identical blastomeres with no fragments or multinucleation).

Jose Franco Jr (Ribeirão Preto, Sao Paulo, Brazil) and colleagues investigated whether “a late adverse paternal effect on embryo development can be avoided through better selection of spermatozoids and IMSI.”

A total of 331 oocytes were selected and injected by ICSI (n = 172), or IMSI (n = 159) where spermatozoa free from morphological abnormality were selected using 8400x magnification.

Measured outcomes were similar for ICSI and IMSI, at 70.9 and 70.4 percent for fertilization, respectively, 66.9 and 60.4 percent for early embryo cleavage rates, and 99.2 and 99.1 percent for overall cleavage rates.

By day 2, both methods had produced a similar proportion of top quality embryos, at 57.8 percent for ICSI and 52.2 percent for IMSI.

The researchers also found that the presence or absence of male factor infertility made no difference to the results.

However, the team concludes: “We cannot exclude the possibility that IMSI effects occur only as a positive later paternal effect.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2010