ICSI and IMSI are techniques used in cases of male factor infertility, with the goal of allowing male patients with low sperm count, poor sperm motility and/or abnormal sperm structure the chance to father a child. Pregnancy and live birth rates for these techniques are similar to IVF success rates for patients with other causes of infertility.
IntraCytoplasmic Sperm Injection (ICSI, Sperm Microinjection)
Following preparation (which is the same as for a standard IVF treatment, including stimulation and oocyte retrieval) a single sperm with normal morphological features is identified using a 400x microscope, and then injected into the center (cytoplasm) of a mature oocyte (held with a pipette) through a specialized needle.
The following morning the egg is tested to see if the procedure resulted in an embryo being created. The created embryos are treated in the same manner as during standard IVF treatments.
ICSI can be useful in cases of low sperm count, low motility, abnormal morphology and presence of high levels of antibodies in the semen (or a combination of thereof), as well as in cases of a previously performed vasectomy. It is the most common technique used to treat male factor infertility.
Intracytoplasmic Morphologically Selected Sperm Injection (IMSI)
In a 2001 a group of specialists led by Prof. Bartoov from Israel developed a procedure called MSOME (Motile Sperm Organelle Morphology Examination) was developed in 2001. It allows the examination of a motile spermatozoon under a powerful microscope, which makes it possible to spot defects which were not detectable under lesser optical magnification, thus ensuring that only the most high-quality spermatozoa are used for egg fertilization. Among the organelles assessed are: the acrosome, postacrosomal lamina, neck, tail, mitochondria and nucleus. Special attention is paid to the nucleus, which is assessed in terms of shape and content (vacuolar area). At Central IVF MSOME is performed under magnification of 6300x.
The development of MSOME facilitated the introduction of IMSI - a microinjection procedure, which is a modification of the standard ICSI method. It is advised for patients with recurrent IVF failures and in cases where high numbers of DNA-fragmented spermatozoa had been detected, and has been found effective in assisting said patients to conceive. For example, Atinori et al. found that patients who had two or more attempts were significantly more likely to succeed with IMSI as their next treatment (29.8% versus 12.9%) and that miscarriage rates for patients receiving this treatment were also significantly lower. It should, however, be noted that as the process is more complex than ICSI, it is also more time-consuming and costly.