Intracytoplasmic Sperm Injection vs IVF
Intracytoplasmic sperm injection (ICSI) and IVF differ in the way that the egg is fertilized. ICSI gives the sperm and the egg a greater chance of fertilization because of its direct approach. This procedure can benefit couples who have a low sperm count, or in situations when the sperm’s movement is impaired.
Intracytoplasmic sperm injection procedure
From the perspective of the mother, the ICSI treatment cycle is just the same as regular IVF. It is only the pre-fertilization stage which differs. During this stage, the embryologist will collect a single healthy sperm with a very delicate hollow needle and insert the sperm into the cytoplasm of a mature egg. The eggs are then monitored for evidence of fertilization.
Who can benefit from intracytoplasmic sperm injection?
ICSI is suitable for a number of scenarios:
- Sperm count is low
- Sperm are unable to move properly
- Sperm has been retrieved surgically
- Semen contains high levels of antibodies
- Previous attempts at conventional IVF have failed
What is conventional IVF?
Conventional IVF is the most common technique for in vitro fertilization. Like ICSI, the fertilization procedure is conducted in a laboratory. The difference is that in conventional IVF, a number of healthy sperm and a mature egg are placed in a dish and mixed together in a culture dish. The sperm is left to fertilize the egg naturally. Fertilization is expected to take place within 16-18 hours.
In both procedures, once fertilization has occurred, the embryos are allowed to grow in the culture for between 3 and 5 days. By this time, the embryos will have reached optimal growth and can be transplanted into the mother’s uterus. If more than five viable embryos are available, a day-5 blastocyst transfer is usually performed as this allows the embryologist time to choose the highest quality embryos.
What happens to spare embryos?
If there are any remaining healthy embryos, the couple has the choice to have them cryopreserved. This is useful in case the current IVF cycle is unsuccessful, or in case the couple decides to extend their family in the future. Cryopreserved embryos may also be donated to other couples who are struggling to start a family. Research shows that ICSI does significantly increase the fertilization rate by up to 10 percent and implantation rates by up to 5% compared to conventional IVF. Couples who are considering using IVF to start a family should talk to an embryologist to see if ICSI is right for them.