In Vitro Fertilisation (IVF)
What is IVF?
The term In-vitro fertilisation or IVF, literally means fertilisation “in glass” and refers to the process where a woman’s eggs are fertilised outside of her body in the laboratory. The resulting embryos are then transferred back into the uterus a few days later.
- Who is IVF suitable for?
IVF is specifically recommended for women with absent, blocked or damaged fallopian tubes. It is also often used in cases of unexplained infertility, in some cases of male factor infertility and can be used in combination with ICSI (intracytoplasmic sperm injection) in cases of severe male factor infertility.
- What does IVF involve?
There are four general steps involved in an IVF cycle:
Stimulation of the ovaries to encourage development and maturation of the eggs
Under the care of a consultant gynaecologist, the woman is given fertility medications to stimulate her ovaries to produce many follicles. Follicles are the small fluid filled structures which develop on the ovaries, each of which will hopefully contain an egg. The number and size of the developing follicles is measured by trans-vaginal ultrasound scans. The exact number of follicles which develop varies between patients, but the average is about 10. The final preparation for egg retrieval involves a hormone injection which mimics the natural trigger for ovulation. Egg retrieval will take place 36-38 hours after this injection.
Retrieval of the Eggs
Egg retrieval is a minor theatre procedure which is carried out in the clinic under local anaesthesia. The trans-vaginal ultrasound probe is used to visualise the ovaries and a needle attached to the probe is passed through the vaginal wall into the follicles. The fluid within each follicle is aspirated and then examined in the IVF laboratory for the presence of an egg. After identification, the eggs are washed and transferred into special culture medium in Petri dishes in an incubator.
Fertilisation of the eggs and culture of the embryos
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.
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 patients, a blastocyst cycle may have been recommended in which case embryo culture is extended to day 5. Any additional embryos that are not transferred on either day 3 or day 5 can be frozen.
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.
- Can you transfer more than one embryo?
During IVF treatment there is an increased chance of multiple pregnancies if more than one embryo is transferred. Research has shown that limiting the number of embryos transferred to two reduces the chances of multiple pregnancies without causing a significant decrease in overall pregnancy rate. It is recommended to transfer a single embryo. In some cases, following discussion with your consultant, it may be appropriate to transfer more than one embryo and this is a decision that will be made between you and your consultant. The maximum number of embryos transferred is two.
- How successful is IVF?
Chances of success vary between patients, particularly according to the age of the woman, but on average about 28% of patients will have a baby after one attempt at standard IVF. Find out more about the IVF success rates at Sims IVF>
Can IVF help me fall pregnant?
To find out whether IVF can help you fall pregnant, please book an appointment with a Sims IVF fertility specialist or contact us.