Intracytoplasmic Sperm Injection (ICSI)
An alternative method of egg fertilization is called Intracytoplasmic Sperm Injection, or ICSI. An extremely sharp glass needle is used to inject one normal appearing sperm directly into the center (cytoplasm) of the egg under the guidance of a specially fitted microscope and the micromanipulator.
Indications for ICSI include men with (1) severely compromised sperm parameters, including low concentration, motility, morphology, or antisperm antibodies; (2) blocked or absence of the vas deferens, where sperms are collected by epididymal aspiration or testicular biopsy for ICSI; (3) couples who had low or failed fertilization on prior IVF attempts; (4) unexplained infertility (causes of couple’s infertility remain unknown after completing all diagnostic testing); (5) certain medication or other medical history. (6) women with less number and quality of eggs
Some couples are fortunate enough to collect large number of embryos from one egg collection. Any additional viable embryos may be frozen (“cryopreserved”) for future use. Cryopreservation allows the patient to limit the number of embryos transferred “fresh” without discarding the unused embryos that could lead to a future pregnancy. The embryos may be kept in storage for several years. By transferring frozen-thawed embryos into the uterus, some patients have achieved 2-3 pregnancies in different years from just one egg collection.
In order for the developed embryo to implant in the uterine wall it must break free of its shell, which is called the zona pellucida.
Some embryos grown in the laboratory may have a harder shell than normal or may lack the energy requirements needed to complete the hatching process. The embryologists can help these embryos achieve successful implantation through a technique called assisted hatching.
On the third or fifth day of the embryo development and just before the embryo transfer, a small hole is made in the zona pellucida of the embryo with a specially fitted laser microscope. Through this opening, the cells of the embryo can escape from the shell and implant when the uterine lining may be more favorable.
Women who are most likely to benefit from assisted hatching are those:
Age above 38 yrs and above
Repeated failed IVF/ICSI cycles
Embryos with abnormal appearing zonae