What is ICSI?

  • ICSI is an acronym for intracytoplasmic sperm injection
    • A fancy way of saying “inject sperm into egg”
  • ICSI is a very effective method to fertilize eggs in the IVF lab after they have been aspirated from the female
  • Its main use is for significant male infertility cases
  • IVF with ICSI involves the use of specialized micromanipulation tools and equipment and inverted microscopes that enable embryologists to select and pick up individual sperm in a specially designed ICSI needle.
  • The needle is carefully advanced through the outer shell of the egg and the egg membrane – and the sperm is injected into the inner part (cytoplasm) of the egg.
  • This usually results in normal fertilization in about 75-85% of eggs injected with sperm.
  • However, first the woman must be stimulated with medications and have an egg retrieval procedure so we can obtain several eggs for in vitro fertilization and ICSI.


Intracytoplasmic sperm injection (ICSI) is an option for couples undergoing IVF. ICSI often boosts in vitro fertilization (IVF) success rates for couples dealing with male infertility. First introduced in 1992, ICSI is probably the greatest advancement in treating infertility since IVF. ICSI offers couples the chance to have their own children when it would be impossible by other means. 


ICSI success rates for live birth

Here are the success rates for couples with a primary diagnosis of male infertility that tried IVF in 2011. A very high percent of these couples (88 percent) chose to use ICSI along with IVF. Here are the birth rates, grouped by the mother’s age, for couples that underwent an embryo transfer with IVF in 2011 and had a diagnosis of male infertility.

  • Women under 35: 48.3 percent 
  • Ages 35 to 37: 42 percent
  • Ages 38 to 40: 29.8 percent
  • Ages 41 and 42: 20.4 percent
  • Over age 42: 7 percent

One key to ICSI’s success is that ICSI improves the odds of fertilization. Approximately 50 to 80 percent of eggs are fertilized during the ICSI procedure. 

Fresh or frozen sperm?
There appears to be no difference in pregnancy rates between those who use fresh or frozen sperm during the ICSI process. Fertilization rates with ICSI range from 50 to 80 percent. However, not all fertilized eggs develop into healthy embryos. Unfortunately, some eggs and embryos do become damaged during the ICSI process. 

ICSI success for male factor infertility
While many couples choose ICSI with IVF, intracytoplasmic sperm injection is primarily indicated for cases of male infertility. ICSI can help you bypass the following problems that may be making it harder for you and your partner to get pregnant:

  • Low sperm count
  • Poor sperm motility (movement) and morphology (shape)
  • Blockage or irreversible vasectomy
  • Sperm unable to penetrate the egg
  • When previous IVF cycles have not worked

If you are undergoing IVF, make sure your partner has a thorough semen analysis before you begin. Know that even if there are no issues with your partner’s sperm, your doctor may still recommend ICSI with IVF. ICSI is becoming more common in IVF clinics because it virtually guarantees that the sperm penetrates the egg.