Fertilization (IVF)
Step by Step IVF Process
Ovaries are stimulated with daily sub cutaneous injection called FSH for about 9-10 days
The Follicular ( Egg ) Growth
Monitored with vaginal ultrasound scans regularly on alternate days interval e.g Day 5 stimulation , Day 7 and Day 9 .
Trigger Day
When the FSH injections are stopped and a single new injection called trigger shot is given to mature the eggs and make them ready for egg Collection ( aka Oocyte Pick Up , OPU ) ; usually timed between 35 to 37 hours after the trigger shot .
Egg Collection ( OPU )
Egg retrieval is a minor procedure which is carried out in our operating theatre under anaesthesia . The trans-vaginal ultrasound probe is used to visualise the ovaries, similar to monitoring scans done during the egg stimulation and a needle attached to the probe is passed through the vaginal wall into the follicles. Each follicle contains an egg and the fluid within the follicle is aspirated into a test tube and passed on to embryologist who then examines the fluid in the IVF laboratory for the presence of the egg. After identification, the eggs are washed and transferred into special culture medium in Petri dishes in an incubator.
Insemination ( Conventional IVF or ICSI )
While the egg retrieval is proceeding, the sperm is also prepared. A semen sample is provided by the male partner and in the laboratory, a concentrated preparation of the best motile sperm is extracted from the semen sample. This sperm preparation (containing approximately 150,000 sperm) is added to the dishes containing the eggs, and they are incubated together overnight. In some couples an alternative form of insemination is required called ICSI, which involves injecting a single sperm into each egg using a very fine needle, rather than mixing the eggs and sperm in a dish Irrespective of the method of insemination used, on the morning after egg retrieval, the eggs are examined to see which have fertilised.
Embryo Culture
Fertilised eggs (zygotes) are then
routinely cultured in the IVF laboratory until day 3, at which time the best 1-3 embryos are selected and transferred back into the woman’s uterus. For some patients, a blastocyst culture may have been recommended in which case embryo culture is extended to day 5.
Embryo Transfer
Embryo transfer is a simple theatre procedure that does not routinely require anaesthesia. The embryos are placed into the uterine cavity by the doctor by means of a fine catheter inserted through the cervix. The correct positioning of the embryos is confirmed by abdominal ultrasound, so the woman is required to have a full bladder for the procedure.
Embryo Freezing
Any additional embryos that are not transferred on either day 3 or day 5 can be kept frozen for future use.
What is ICSI?
Intracytoplasmic sperm injection (ICSI) is an additional procedure in IVF process as compared to the conventional method. The difference between the two procedures i.e Conventional IVF and IVF / ICSI is the method of achieving fertilisation.
ICSI is a laboratory procedure done by our skilled embryologist , where a single sperm chosen by its normal morphology and good motility to be directly injected into each egg . As each egg requires only a single sperm , only a few sperm are required for IVF/ICSI , as compared to conventional IVF where about 100,000 sperm are inseminated with each egg to allow fertilisation to occur . ICSI increases the chances of fertilisation although it doesn’t guarantee that it will occur as normal cellular events are required to have fertilisation to happen once the sperm has been placed into the egg.
Who should ICSI be used for ?
As ICSI is an additional procedure in an IVF cycle , there are a few clinical indications where we would advise for ICSI . Not everyone needs ICSI and the common indications are :
1.In severe oligospermia ( very low sperm counts )
2.Sperms retrieved via SSR
3.Men with high antibody levels in their semen
4.Previous failed fertilisation in a Conventional IVF cycle
5.Multiple unsuccessful IUI cycles