ICSI - Intracytoplasmic sperm Injection

ICSI Treatment Stage 5-Embryo Replacement

It is at the embryo transfer that the discussion of the number of and quality of embryos to be replaced will take place. The embryo replacement normally takes place with no sedation. It is similar to a smear test in that a speculum is passed into the vagina. The vagina is then cleaned whilst the embryologist loads the catheter containing the embryos. A fine caterer containing the embryo/ embryos is passed through the cervix and into the uterus. The embryo's are deposited in the uterus. This is performed under ultra sound guidance. A pregnancy test should be performed 14 days after Embryo transfer.

4 Cell Embryo

Progesterone

Progesterone helps to maintain the thickness of the lining of the uterus to aid implantation. The lining will have been increasing as a result of the FSH injections. This drug will be taken in the form of intra- muscular injection or suppository prior to or commenced on the day of the embryo transfer and continued until the pregnancy test.

Cryopreservation of Embryos

Following an IVF or ICSI cycle couples may have spare embryos that are of a good quality. The unit may then offer to cryopreserve the embryos for a frozen embryo replacement cycle.

The embryos have to be of a certain quality otherwise they will not survive the freezing or thawing process. Therefore not all couples will be offered freezing at the embryo replacement cycle. Some of the criteria the embryologists will be looking for are:

• Number of cells present in the embryo
• The number of cells correlating to the development stage of the embryo
• Degree of fragmentation in the embryo
• Number of embryos available for freezing-There may be a minimum number of embryo’s that a unit will freeze

Once the embryos have been preserved then they can be stored by the unit until a couple are ready to proceed with another treatment cycle.

The Frozen Embryo Replacement Cycle

Unlike IVF or ICSI a Frozen Embryo replacement cycle does not require the ovaries to be stimulated. Instead Oestrogen is administered, normally in tablet or patch form. This enables the uterine lining to develop for the embryo’s to be replaced. Vaginal scans will also be performed to check that the lining is thickening as result of the Oestrogen theraphy. When the lining has reached approximately 8mm in thickness, the replacement of the embryos will be scheduled. The unit will then advise the woman when to commence Progesterone which will help to maintain the uterine lining. Both Oestrogen and Progesterone are continued until the pregnancy test 14 days after embryo transfer.

Uterine Lining

It is on the day of the embryo replacement that the embryologists will thaw the embryos for the transfer. In some cases, not all of the embryos cryopreserved will thaw successfully.

Blastocyst transfers

More evidence is suggesting that patients who have undergone multiple treatment cycles without a successful outcome, having had good quality embryos may benefit from a blastocyst transfer. Women who are at risk of multiple pregnancies may also benefit as one blastocyst is normally transferred.

Blastocyst transfers are normally performed on day 5, rather then day 2 or day 3, following egg collection. The criteria do vary from clinic to clinic but normally four good quality embryos of 8 cells on day 3 following egg collection are required.

Hatching Blastocyst

There are some risks involved by delaying transfer. One of those is that the embryos may not develop to the blastocyst stage. Therefore there may not be an embryo transfer. Blastocyst transfer is allowing the embryos to reach a more mature stage of development and some may not have the potential to do so. They will therefore cease to develop further.

Risks to the children born from blastocyst transfer are still being studied, as it is still a relatively new procedure. However there is evidence to suggest that the chances of identical twins are higher as well as the chances of conceiving a boy.

Freezing of Blastocysts

The freezing of embryos depends on the quality of the embryos. The embryo quality has to be high for them to survive both the freezing and thawing process. Blastocysts have reached a stage of maturity where they are ready to implant therefore clinics offer the freezing of all blastocysts.

Effects of ICSI

ICSI is still a relatively new procedure therefore the research on the effects that it may have on children born is still limited. It is possible that male children born may inherit the same type of infertility that the male partner presented if the sperm production was affected by a chromosome abnormality. Genetic counselling should be offered in such cases.