Intra Cytoplasmic Morphologically Selected Sperm Injection (IMSI)


What is IMSI?

Intra Cytoplasmic Morphologically Selected Sperm Injection (IMSI) is an advanced variation of the standard Intra Cytoplasmic Sperm Injection (ICSI) technique used in assisted reproductive technologies. IMSI is a highly specialized procedure that involves using an advanced microscope to select and inject a single sperm into an egg during in vitro fertilization (IVF). The key difference between ICSI and IMSI lies in the level of sperm selection and evaluation.


How IMSI works:

  1. Ovulation Stimulation and Egg Retrieval: The process begins with the same steps as conventional IVF, which includes stimulating the woman’s ovaries to produce multiple eggs and retrieving mature eggs through a minor surgical procedure.
  2. Sperm Collection: A semen sample is collected from the male partner or a sperm donor. This is similar to the standard ICSI procedure.
  3. Advanced Sperm Evaluation: What sets IMSI apart is the advanced evaluation of sperm quality. In IMSI, the collected sperm is assessed under a high-powered microscope known as a motile sperm organellar morphology examination (MSOME). This microscope allows for much higher magnification and resolution compared to traditional microscopes used in ICSI.
  4. Sperm Selection: During the MSOME evaluation, the embryologist can carefully assess the sperm for various factors, including morphology (shape), motility (movement), and the presence of any abnormalities or defects. Only sperm with the best morphology and the fewest defects are selected for injection.
  5. Sperm Injection: A single, carefully selected sperm is injected into the egg’s cytoplasm using a micropipette, similar to the ICSI procedure.
  6. Embryo Culture and Transfer: Fertilized eggs are cultured in the laboratory for a few days, and one or more healthy embryos are transferred into the woman’s uterus.


IMSI is designed to address cases of male infertility where conventional sperm evaluation techniques might not identify subtle abnormalities in sperm morphology and structure. By using high-resolution microscopy to select the sperm, IMSI aims to improve the likelihood of successful fertilization and potentially improve embryo quality.


While IMSI may be beneficial in specific cases of male infertility, it is not always necessary or appropriate for all couples undergoing IVF. Your fertility specialist will determine whether IMSI is suitable for your situation based on a thorough evaluation of your reproductive health and the quality of the sperm.


It’s essential to consult with a fertility expert to discuss the most appropriate assisted reproductive technology for your unique circumstances and needs.