Introduction
As the name implies, In vitro fertilisation (IVF) is the process of creating an early pregnancy, or blastocyst in the laboratory for later transfer to the woman’s uterus.
Procedure
IVF is a step wise procedure, and therefore is most easily understood as a step-by-step process. IVF cycles are jointly managed by the IVF nurses, who co-ordinate the steps in the cycle, and Dr Friebe, who will perform the egg pick up procedure and also the embryo transfer.
Step 1 – Stimulation of Egg Development
Artificial versions of the Follicular Stimulating Hormone (FSH), secreted by the pituitary gland to stimulate the formulation of the egg, and the Luteinizing Hormone (LH), also secreted by the pituitary gland to mature the egg are used in the IVF cycle.
The FSH injections are commenced on Day 2 of the menstrual cycle (Day 1 being the first day of the period), and are continued daily until a “trigger” injection called Ovidrel is given to mimic the body’s natural LH surge and mature the eggs to be ready for collection. Another injection, called an “antagonist” is introduced about day 8 of the cycle to effectively turn off the pituitary gland to prevent ovulation of the developing eggs before they can be collected.
The dose of these medications will be determined by Dr Friebe prior to the cycle commencing. A transvaginal ultrasound is usually performed around Day 9 to both count the number of follicles present in the ovaries, and to determine the time and date for the trigger injection to be given, and then the egg pick up to be performed 36 hours later once the eggs are matured and ready for collection.
If the ovaries have too many follicles present (over 20), the patient is at risk of Ovarian Hyperstimation Syndrome (see later), and the type of trigger will need to be changed from Ovidrel to an alternative to prevent this happening. All embryos from the cycle will also need to be frozen and used later – once the ovaries have returned to normal.
The nurses at LIFE fertility provide clear written directions, and excellent support through the stimulation phase. Dr Friebe can of course be contacted for any queries or concerns at any stage.
Step 2 – Egg Retrieval
The egg retrieval procedure is performed under a light general anaesthetic in the hospital operating theatre. An ultrasound probe is placed into the vagina with a special guide attached, which allows a needle to be placed under ultrasound vision into each follicle in the ovary, to drain the fluid in each follicle and collect the eggs present. Not every follicle will necessarily have an egg present.
The eggs are isolated from the follicle fluid by the IVF scientist, and are then placed into a culture medium. The eggs are then taken back to the IVF lab for insemination.
The procedure is usually straightforward and takes 15-20 minutes. Most patients will have only minimal pain after the procedure and maybe some light vaginal spotting. Heavy bleeding or troubling pain after the procedure should be reported to Dr Friebe.
Step 3 – Sperm Collection
On the day of egg collection, where appropriate, the male partner will be asked to produce a semen sample, around the time of the egg retrieval. The semen sample may be collected at home if this is no further than 1 hour travelling time from IVF clinic – otherwise, there is a designated private room for this purpose at the clinic. Specific instructions will be given regarding semen collection, including an appointment time to produce or drop off a sample at the clinic. Two to seven days abstinence from ejaculation is recommended prior to producing this sample.
If it’s not possible for a sperm sample to be produced on the day of egg retrieval, the sperm can be frozen prior and thawed out on the day.
Some men do not produce sperm in their ejaculate even though sperm is being produced in the testis. For these patients a procedure called Percutaneous Epididymal Sperm Aspiration (PESA) or Testicular Sperm Aspiration (TESA) may be used to surgically retrieve sperm. Both procedures can be done through LIFE fertility and will be arranged in advance by your clinician and Nurse Coordinator.
Step 4 – In Vitro Fertilisation and Intracytoplasmic Sperm Injection (ICSI)
Once the semen sample has been received by the laboratory the sperm is prepared to optimize its quality and this is used to inseminate the eggs
For standard IVF insemination, a large number of normal motile sperm must be present in the sperm preparation to optimise the chance that fertilisation will occur. If a suitable number of sperm are available, the sperm preparation is added to the eggs in the culture dish, and they are cultured together overnight.
If the number of sperm in the sperm preparation is too low for standard IVF however, or if they are of suboptimal quality in some way, a procedure called intra-cytoplasmic sperm injection (ICSI) can be used, whereby a single sperm is injected into each egg.
The next day, each egg is checked for fertilization and the results are conveyed by phone by the laboratory scientist. Not every egg will fertilise, and about 5% of the time, none will fertilise at all for reasons that are usually unknown. Each day the developing embryo will be checked until it reaches day 5, when it is called a blastocyst and is ready for transfer. Not every egg will become a blastocyst, some will stop developing before day 5 and will fail. It is important to remember that quality of the egg is important as well as quantity.
Step 5 – Embryo transfer
The embryo transfer is the final step of the IVF cycle and is performed in the LIFE fertility rooms. The embryo transfer is performed under ultrasound guidance, (with the woman having a full bladder), via a probe placed on the abdomen so both the woman and clinician can see the embryo placed in the correct part of the uterus.
A speculum is inserted into the vagina, the same as at a pap smear, and a thin plastic tube called a transfer catheter is passed through the woman’s cervix to allow access to the uterine cavity. The IVF scientist uses a syringe to pick up the embryo(s) into the tip of the embryo catheter. The clinician then carefully passes the catheter through the cervix into the uterine cavity and the embryo(s) are deposited in the uterus. The process lasts only a few minutes and does not normally require an anaesthetic. After the embryo transfer, the woman will need to keep using vaginal progesterone cream or pessaries for 2 weeks until a pregnancy test is performed to see if the cycle has been successful. The IVF nurses will clearly explain what needs to be done after the transfer.
Couples who have more embryos than they can use may have any ‘extra’ good quality embryos frozen for their future use. However, to do so, the couple must have signed the appropriate consent forms.