What is in vitro fertilisation and how does it work?
In vitro fertilisation was originally developed to assist conception in women who have blocked or damaged fallopian tubes but, because of its success rates, is now being used to treat other causes of infertility, such as sperm disorders and endometriosis.
In vitro fertilisation involves adding prepared sperm to a dish containing eggs. The sperm swim to the eggs and attempt to fertilise them. Once fertilised, the embryos are monitored and transferred back into the uterus at the correct time, typically between two and five days after the egg collection, depending whether you have embryos returned at blastocyst stage.
Natural cycle IVF
Natural cycle IVF consists of IVF, with or without ICSI, carried out in an unstimulated cycle. This means that no drugs are used to make the ovaries produce multiple eggs, although drugs are given to time egg retrieval.
This procedure relies upon the natural growth of one follicle, which means spontaneous ovulation may occur before egg collection. This single egg might not be retrieved, or might not be of sufficient quality to be used, or it may fail to fertilise. For these reasons the success rate of natural cycle IVF/ICSI (about 7% per cycle) is lower than for stimulated cycles.
Natural cycle IVF is sometimes used in circumstances where ovarian stimulation (or the use of drugs for ovarian stimulation) is not possible; where ovarian stimulation confers no benefit; or where the patient chooses not to have stimulation. Natural Cycle IVF is not available at IVF Scotland.
Is IVF for me?
IVF is often recommended if:
- you have been diagnosed with unexplained infertility
- your fallopian tubes are blocked
- you have been unsuccessful with other techniques, such as fertility drugs or intrauterine insemination (IUI)
- there is a minor degree of male subfertility – more severe problems are treated with intracytoplasmic sperm injection (ICSI).
Semen sample production
It is policy that all partners, if applicable, produce their semen sample at the centre. We have rooms specifically designed for donation purposes. In exceptional circumstances home donation or donation in a hotel may be accepted but it is important that you discuss this with your fertility specialist during consultation.
Once the male partner has produced his semen sample he will be required to stay at the centre until our laboratory has analysed the quality of his sperm. If the sample is not of sufficient quality the embryologist and doctor will discuss other options with you.
What to expect once you undergo treatment
Our individualised approach means that every couple will vary in how their treatment is planned and managed. However, the following information may help to give you an idea of what can be expected.
When undergoing treatment, women will be given a course of fertility drugs. The type of course of drugs you undergo will be determined by your fertility specialist based on your individual clinical needs.
You may be advised to go on a short course of drugs, known as an antagonist protocol. In this instance you will start your stimulation injections on day 2-3 of your menstrual cycle with another type of injection added on day 6. Both will then be continued for an average of 14 days before you are ready to have your eggs collected.
Alternatively, if you are advised to go on a longer course of drugs, known as an agonist protocol, you will be given an ovarian suppressant injection seven days before your period is due and then injections of gonadotrophin for 10-14 days (starting on day 5-12 of the following period) to stimulate the development of follicles which contain eggs on the ovaries. A final, single injection of hormone is given 36 hours before your planned egg collection to ripen and mature the eggs prior to their removal.
During the cycle of drug treatment you will be monitored very closely in order to determine the ideal timing for egg collection. Ultrasound scans are performed regularly (approximately two or three times per week) in the run-up to egg collection in order to see the developing follicles. Blood samples may also be taken to measure hormone levels along with the scans.
The egg recovery is a short procedure, taking approximately 30 minutes, and uses a fine needle inserted through the upper vagina, guided by a vaginal ultrasound probe, to collect your eggs. Sedation is given to aid relaxation and minimise discomfort. Most women will be able to leave the clinic within three to four hours of this procedure.
Your eggs are mixed with your partner’s or donor’s sperm and cultured in the laboratory for 16-20 hours. They are then checked to see if any have fertilised.
Those that have been fertilised (now called embryos) are grown in the laboratory incubator for up to five days before being checked again. The best embryos will then be chosen for transfer. The law allows a maximum of two embryos for women below 40 years of age and maximum of three embryos for women of 40 years and above. However, please refer to the Risks of Multiple Births Information Sheet for more information.
Embryo transfer is a simple and painless procedure, which involves the transfer of fertilised embryos via a fine catheter inserted through the cervix into the uterus. Embryo transfer is usually carried out with the use of an ultrasound scan.
Following embryo transfer you will undergo additional hormone treatment, receiving progesterone until a pregnancy test is performed 14 days after the egg collection. Progesterone can be administered as an injection, or vaginal or anal pessaries or suppository. You will return to the centre for a pregnancy blood test 14 days after the egg collection has taken place, regardless of whether you have begun a period.
Following a positive pregnancy test, you will have a scan three weeks later. If the pregnancy test is negative, you will be offered a follow-up appointment with one of our fertility specialists to discuss your future fertility options.
Are there any risks with IVF?
It is very important that you are fully aware of all the potential risks involved prior to going ahead with IVF treatment. The risks will be explained by your nurse or fertility specialist and you will be given an opportunity to ask questions.
The risks associated with IVF are:
- A mild reaction to fertility drugs may involve hot flushes, feeling low of mood or irritable, headaches and restlessness.
- Ovarian hyperstimulation syndrome (OHSS) is a serious over-reaction to fertility drugs used to stimulate egg production. It can cause symptoms such as a swollen stomach, stomach pains, nausea and vomiting. If you start
to experience any of these symptoms you must contact the centre immediately.
- The risk of miscarriage following IVF is the same as in natural conception.
- There is a risk of ectopic pregnancy following IVF. When an embryo develops in your Fallopian tube rather than your womb the pregnancy is said to be ectopic. Ectopic pregnancy can cause vaginal bleeding and low pregnancy hormone levels. Hormone tests and scans are used to detect ectopic pregnancies and you should tell your doctor about any vaginal bleeding or stomach pain.
- The biggest risk associated with IVF is the risk of multiple pregnancies. Please refer to Information on the Risks of Multiple Births for more information.
What are my chances of success with IVF?
Female fertility diminishes with age and, on average, the younger you are the higher your chances of success. The national average success rate for live births in 2007 (HFEA) for women receiving IVF or ICSI treatment using their own eggs were:
- 32.3% for women under 35
- 27.7% for women aged between 35-37
- 19.2% for women aged between 38-39
- 11.9% for women aged between 40-42