IMSI (Intracytoplasmic Morphologically Selected Sperm Injection)
One aspect of male fertility which can be measured and which relates to fertility is the level of abnormalities present in the sperm. Such abnormalities result in poorer quality sperm which in turn may reduce the possibility of fertilisation of an egg and have also been shown to effect the health of an embryo from which a pregnancy can occur.
Many sperm abnormalities can be identified by the embryologist using a normal microscope with magnification x400-600. This is used when ICSI treatment is performed .However, by looking at sperm using much higher magnifications ( up to x6000) coupled with a digital imaging system, it has recently become possible to identify structures within the sperm head known as vacuoles which can not be seen with a normal microscope. The presence of these sperm head vacuoles relates to an increased incidence of poor DNA arrangement within the sperm. Selecting sperm using IMSI can help to reduce the possibility of injecting a sperm with damaged DNA into the egg.
Recent research has shown that sperm selection using IMSI is associated with better embryo quality, higher pregnancy and lower miscarriage (Antinori et al, 2008; Bartoov et al, 2002)
CRM London was the first centre in the UK offering IMSI and we have presented our results at the Fertility 2011 conference in Dublin in January. Our results do support the higher pregnancy rate that previous studies have shown.
Currently we recommend that IMSI may be useful for the following patient groups:
- Male partners over 35 years
- Patients whereby the semen analysis has identified a high number of abnormally formed sperm
- Patients that have not achieved good quality embryos in previous cycles (if not related to egg quality)
- Patients with previous unsuccessful treatment cycles not due to an apparent egg factor
- Patients with a history of miscarriages