Intracytoplasmic sperm injection (ICSI) is very similar to IVF, except that a single sperm is injected directly into the egg rather than simply mixing sperm and eggs.The fertilisation and pregnancy rates are similar for ICSI as they are for IVF. ICSI will generally be used in cases of poor sperm quality or in exceptional circumstances when there has previously been poor fertilisation with IVF or if there are antibodies to sperm present in the semen.
Embryo culture and transfer
As with IVF, once embryos have been created in the laboratory, they will be cultured in an incubator where they will undergo cell division. The day of embryo transfer is usually determined by embryo quality and you will be kept up to date on this by one of the nursing team. Embryo transfer is performed either on day 3 of development when the embryo has around 8 cells, or on day 5 at the blastocyst stage when the embryo has >100 cells.
Single embryo transfer
We encourage all our patients to have an elective single embryo transfer, as it is much safer to have a single baby rather than twins. The risk of twins is more than 20% of all pregnancies if two good quality embryos are transferred, so it is important to take this into account in discussions with your doctor.
Embryo freezing
Any good quality embryos which have developed but not replaced can be frozen for use later, with your consent. This is an efficient process and the pregnancy rate using frozen-thawed embryos is very good. This is especially important when discussing issues around single embryo transfer.
You will be given detailed information on all aspects of your treatment before your treatment. There is also information on ICSI and blastocyst transfer – just ask our nursing staff.
