What is IMSI: Intracytoplasmic Morphologically-selected Sperm Injection?
Dr Chaithra S K
Kalyan nagar, Bengaluru Feb 14, 2017
One aspect of male infertility which can be evaluated is the level of irregularities present in the sperm. Such irregularities result in poor quality sperm which in turn diminishes the chances of fertilization of an egg.
They have also been shown to alter the genetic makeup of an embryo which in turn could result in miscarriage.
The Intracytoplasmic morphologically-selected sperm injection, better known as IMSI for its acronym in English, is a laboratory technique used in IVF treatments and involves highly selective sperm injection into the egg.
Most sperm abnormalities can be diagnosed by the embryologist using a normal microscope with 400-600x magnification, normally used when ICSI treatment is performed.However, analyzing a sperm using much higher magnifications (up to x6000) along with a digital imaging system, it has become possible to identify structures in the sperm head, called vacuoles which can hardly be seen with a normal microscope.
The presence of these sperm vacuoles relates to decreased fertilization rates and implantation rates.
Selecting sperm using IMSI can aid to reduce the possibility of injecting a sperm with flawed DNA into the egg.
Recent research has shown that for few groups of patients’ sperm selection using IMSI resulted with better embryo quality, higher pregnancy and reduced miscarriage rates.
IMSI can be used for the following patient groups:
• Male partners over 40 years
• Patients for whom the semen examination has identified a high number of flawed sperms or patients with high DNA fragmentation index.
Patients with previous fertilization failures by IVF or ICSI
• Patients that have not accomplished quality embryos in previous cycles (if not associated to egg quality)
• Patients with previously failed treatment cycles (if not related to egg quality)
• Patients with previous miscarriages
With IMSI, even minute abnormality of sperms can be picked thereby we can use the best quality of sperms for injection into eggs which gives best results.