In-Vitro Fertilisation or IVF refers to the use of laboratory techniques to bring the egg and sperm together outside of the woman's body. The IVF treatment cycle generally involves several stages.
Most women produce only one egg each month. To increase the number of eggs produced for IVF, and hence the number of embryos that can be formed through IVF, hormonal injections are given. There are many IVF regimes possible. One IVF regime which provides most convenience to the patient involves the use of a Follicle Stimulating hormone (FSH) from the 2nd day of the menstrual cycle. The injections are given daily throughout the IVF ovarian stimulation stage which should last normally between 10 to 12 days. Once the eggs are of a certain size, a second injection is introduced to prevent the eggs from being released on their own.
Women may come to the Centre every day for their injections, but as the needles used are very small, most find it easier to learn how to give self-injections, or get their husbands to do it.
To decide when the eggs are going to be ready for IVF, scans and blood tests are performed once every few days during the IVF ovarian follicle monitoring stage in order to assess the growth of the developing eggs. The scans are usually done trans-vaginally using a long and slim probe. Blood tests are also done to check for levels of certain hormones (oestradiol and LH) produced by the ovary and the brain. These tests give us a good idea of the health of the developing eggs and help confirm the best timing for the next IVF treatment stage which is retrieval of the eggs for IVF.
The dose of the hormones injected may have to be adjusted so as to allow optimum growth of the eggs for IVF. When the blood tests and ultrasound scans indicate that the follicles and eggs are ready for collection, a special injection called hCG is given to trigger the process of final egg maturation. Egg recovery is performed 34 to 36 hours after the hCG injection.
Once the oocytes or eggs have reached a minimum size of 17 to 18mm, they should be ready for fertilisation with the sperm. Oocyte or egg retrieval for IVF is done under sedation or a general anaesthetic. The procedure is generally pain free and the eggs are retrieved from all the follicles seen through a fine needle attached to a vaginal ultrasound probe. Generally, most patients go home a few hours after the procedure with some antibiotics to minimise any chance of infection.
On the same morning that the woman goes for the egg collection, the husband has to produce a semen sample. To ensure that the specimens are of the best quality he should have abstained from sexual intercourse for 3 to 5 days before the day of collection. A course of antibiotics would also be prescribed to him to lessen the chance of any bacterial contamination for 2 weeks prior to this. Sterile specimen bottles for the semen should be collected before the egg collection. It is important that the specimen be kept warm at all times and to reach the clinic as soon as possible. Some husbands may have difficulties producing the sperm specimens without their wives' help and special arrangements can be made to collect and freeze the sperm before hand.
In the laboratory, the sperm sample is prepared and inspected. The most active and motile sperm is then chosen to inseminate the egg. This can be done either by mixing the egg with a known amount of sperm (traditional IVF) or by intra-cytoplasmic sperm injection (IVF-ICSI). ICSI involves injecting a single sperm into each egg via a microneedle to facilitate fertilization. IVF-ICSI is recommended for cases in which there is very poor sperm quality. IVF-ICSI can also be offered in addition to traditional IVF to increase the success rate of fertilization. The cells in the fertilised eggs divide everyday and are inspected daily by the Embryologist, who will ensure the best conditions to help them grow.
Once the embryos formed from IVF are ready for transfer into the womb you will be notified. The exact day and time will depend on the quality of the embryos. The embryologist who has been nurturing the embryos will determine the most suitable day for transfer of the embryos back into the womb. The embryologist is also able to select the best quality embryos for transfer.
Embryo transfer is generally a painless procedure and usually no anaesthetic required. A full bladder however is needed during the procedure in order to ensure a smooth transfer. The embryos are placed back into the womb through the cervix using a very thin, soft plastic tube. This procedure is similar to having a Pap smear.
Usually, 1 to 2 embryos are replaced. The limits are determined by the Ministry of Health, Singapore. The chances of pregnancy increase with the number of embryos transferred but so does the incidence of multiple births, hence the need for the control.
After the procedure, you should not do anything strenuous for the following few days. Hormonal medication will be given to you to support the anticipated pregnancy. Blood tests are performed 17 days after the embryo transfer to confirm pregnancy. Some bleeding from the vagina can occur even though you are pregnant, so it is important to do this test even if you think you are having your period.
It is important to realise that not every IVF cycle results in a successful pregnancy. Failure in one IVF cycle does not mean that you have a reduced chance of success in the next IVF cycle.
Any extra embryos that are not transferred from the initial 'fresh' IVF cycle and are of sufficiently good quality may be frozen for future use. For patients who have embryos frozen after the fresh IVF cycle, they can call upon them if their fresh IVF cycle fails, or after they deliver and want to get pregnant again. The embryo storage needs to be renewed annually, up to a maximum of 5 years. Further storage requires approval from the Ministry of Health.
The thaw IVF cycle may be 'natural' or 'artificial'. For 'natural' thaw IVF cycles, you will be monitored to see when you ovulate. The egg in that cycle will not be collected but based on the time of ovulation, the embryos will be thawed for replacement. The embryo replacement is a simple procedure, similar to that in the fresh cycle.
If there is difficulty in having a good ovulation, an 'artificial' thaw IVF cycle may be advised. Here, hormonal medication will be given and the embryos will then be timed for transfer when the womb lining is of sufficient thickness. If you are pregnant through IVF cycles, you will need to continue on the hormone medication until the pregnancy is at least 10-12 weeks.
The success rate for IVF is age-dependent. Generally, the pregnancy rate for IVF is up to over 40% for the younger age group, but falls to 15% once the woman reaches 40 years. Live birth rates after IVF are around 30% for the younger age group and 5-10% for the older patients.
In order to increase IVF success rates, a thorough gynaecological evaluation is important before commencing on an IVF cycle. Laparoscopic or minimally invasive key-hole surgery may sometimes be recommended before IVF for the treatment of swollen fallopian tubes, fibroids, ovarian cysts and endometriosis.
A hysteroscopy involving the use of a camera device to assess the uterine cavity may also be needed before IVF to ensure a healthy environment for the implantation and growth of the embryos transferred.
To maximise the success rate of IVF as with IUI, couples should enhance their health as much as possible. Any chronic medical conditions e.g. diabetes, should be brought under control before IVF treatment. A healthy diet and lifestyle should be observed. Couples should not smoke and should reduce their intake of alcohol and caffeine. A regular exercise regime can help to control their weight and provide stress reduction benefits for IVF as recommended by our IVF Clinician.
Men should avoid hot baths, saunas and jacuzzis as sperm quality is badly affected by high temperatures. Men should also avoid medications that can adversely affect their sperm function. Antioxidant supplements with vitamins A, C and E should be taken to improve the sperm quality as much as possible as both healthy sperm and egg are important for IVF success.
Women should ensure they are immune to rubella before undergoing IVF treatment because infection during pregnancy can lead to congenital birth defects. They should also take folic acid to prevent birth defects such as spina bifida.