ICSI is an acronym for intracytoplasmic sperm injection when during IVF, a single sperm is injected directly into an egg.

What is ICSI?

ICSI is an acronym for intracytoplasmic sperm injection when during IVF, a single sperm is injected directly into an egg.

During natural fertilization in the body, the head of many sperm must first attach itself to the outside of the egg. Once attached, a single sperm then pushes through the outer layer of the egg to the inside of the egg (cytoplasm).

egg fertilization diagram
IVF illustration

What fertility problems can ICSI address?

In addition to overcoming wall penetration, the ICSI procedure helps to overcome other fertility problems and conditions, such as:

  • The sperm may have weak movement (motility and progression) and is unable to reach the eggs
  • The male partner produces too few sperm (oligospermia) for traditional IVF or intrauterine insemination (IUI)
  • A blockage in the male reproductive tract (ejaculatory duct obstruction) may keep sperm from getting out at all
  • Improved outcomes when In vitro matured eggs are being used
  • Improved outcomes when previously frozen eggs are used
  • Traditional IVF has not resulted in fertilization (failed fertilization), regardless of the apparent health of the sperm
  • Standard utilization in some embryology laboratories

How does ICSI work?

An egg may be fertilized with IVF in insemination and ICSI. With both treatments, a female patient is given medications to produce multiple eggs for retrieval, and fertilization takes place in the laboratory.

During IVF with insemination, approximately 50,000 or more motile sperm are placed in a laboratory dish with an egg. Fertilization occurs when one of these sperm enters the cytoplasm of the egg.

With ICSI, an embryologist picks up just one selected individual sperm with a fine needle called a micropipette. The needle containing the sperm is then carefully inserted through the outer shell and membrane of the egg, and the sperm is injected inside the cytoplasm.

What is the fertilization success rate of ICSI?

IVF with ICSI has a fertilization success rate of 80%-90%. 

How many days before the fertilized egg is transferred to the uterus?

Once IVF fertilization occurs, either by insemination or ICSI, the fertilized egg (now called an embryo) is cultured in the laboratory for 1 to 5 days before it is transferred to the uterus for implantation.

Is ICSI right for you?

We have helped many intended parents achieve pregnancy success at Lane Fertility Institute using IVF with ICSI. Call our clinic today to learn more.