Ovulation Induction | Intra-Uterine Insemination (IUI) | In Vitro Fertilisation (IVF) |
Intracytoplasmic Sperm Injection (ICSI) | Pre-Implantation Genetic Diagnosis/Screening (PGD/PGS) | Assisted Hatching | Sperm Freezing | Embryo freezing | Oocyte (“egg”) freezing
This is where medication is used either to induce or enhance ovulation. The medications used can be injectable or in tablet form and your doctor will decide which is the most appropriate. The treatment is done in conjunction with a tracking cycle and timed intercourse.
This form of treatment can be used for the following reasons:
- If you’re not ovulating
- If ovulation is sub optimal
In this treatment, a semen sample from the male partner is prepared in our laboratory. In this preparation, the motile sperm are isolated from the seminal plasma. The preparation is then drawn up into a fine-tube (catheter). This is then passed through the woman’s cervix and the contents placed into the uterus.
This treatment is often used in conjunction with some stimulation of the ovaries with injections of medications called gonadotrophins.
This form of treatment can be used for the following reasons:
- Poor cervical mucus or problems in sperm passing through the cervix into the uterus. IUI therefore by-passes this barrier;
- Slightly reduced sperm quality, so that those sperm present can be concentrated and placed into the uterus;
- Male partner is not present (e.g. working interstate/overseas) – sperm can be frozen and stored in advance, then thawed out and prepared on the day of the woman’s IUI treatment;
- Antisperm antibodies (ASAB): ASABs can affect sperm motility and the ability of sperm to penetrate the egg. If in a mild form IUI may be appropriate;
- Unexplained infertility.
IVF was first used to treat women with blocked or damaged fallopian tubes.
It involves extracting mature eggs from the ovary after taking higher doses of gonadotrophins and undergoing an ‘egg collection’ procedure – which is performed in the operating theatre. These are then placed in culture in the laboratory and fertilised with the partner’s sperm. The resulting embryos can then be transferred back to the uterus several days later, or frozen for later use.
The success of IVF has improved markedly over recent years and can therefore be used to treat many forms of infertility, including:
- Blocked/damaged fallopian tubes;
- Sperm problems – too few sperm, poor motility, reduced normal morphology;
- Antisperm antibodies;
- Pelvic anatomy disorders;
- Particular endocrine disorders, including polycystic ovarian disease;
- Unexplained infertility.
Blastocyst stage transfer
An embryo can be transferred at varying stages, ranging from a single cell (two pronucleate stage) through to the blastocyst stage. Different centres have different philosophies regarding the day and stage an embryo should be transferred.
The selection of early embryos ( 4 – 8 cell stage) for transfer is not always easy, as many embryos may look very similar under the microscope. However, of these early embryos, only 40% – 50% will grow through to the blastocyst stage. It is thought that many of the embryos that fail to advance to the blastocyst stage are genetically abnormal and thus degenerate early in culture. Therefore, those embryos reaching the blastocyst stage are more likely to be viable and may have a better chance of implantation.
Our centre encourages patients to consider blastocyst culture if they have two or more embryos in culture. Our data demonstrates that blastocyst stage transfer is more likely to culminate in a pregnancy than transferring early cleaving embryos.
The number of embryos for transfer:
It is often thought that the more embryos that are transferred the more likely you are to become pregnant. This is quite misleading. Certainly, in the early years of IVF the chance of achieving a pregnancy per embryo transfer was quite low and this could be improved somewhat by increasing the number of embryos transferred to the uterus.
IVF technology has improved dramatically in the last few years, principally due to improvements in embryo culture and laboratory techniques. For this reason, the scientist is more able to select a viable embryo for transfer, thus circumventing the need to transfer multiple embryos on each occasion.
The multiple pregnancy rates in the general population are around 2%. Following IVF with two embryos being transferred the multiple pregnancy rate is as high as 18%. Multiple pregnancies carry a number of risks, including miscarriage, pre-term birth, cerebral palsy and increased mortality and morbidity for the mother.
Our centre has a policy of transferring a single embryo per transfer. There are two instances where the number of embryos for transfer may be increased to two, after consultation with your doctor:
- Maternal age is ≥ 40 years of age;
- The woman has had ≥ 3 embryo transfers without success.
This is a form of IVF. Where there is an indication that the eggs may not fertilise, the scientists in the laboratory can inject a single sperm into each egg to optimise fertilisation. It is therefore mainly used in the following circumstances:
- Poor sperm quality;
- No sperm in the semen sample – ejaculate (called azoospermia). Sperm can be extracted directly from the testis for fertilisation. Unfortunately these sperm are quite immature with poor motility. Therefore ICSI is required to achieve fertilisation.
- Previous reduced or failed fertilisation in an IVF attempt.
This is a relatively new form of infertility treatment.
For women with polycystic ovarian disease (PCO or PCOS/PCOD), there maybe side-effects (including ovarian hyperstimulation syndrome, OHSS) when being treated by standard IVF technology. This is because the polycystic ovary is sensitive to the drugs that we use for ovarian stimulation, often resulting in over or under response (no or few eggs collected through to too many eggs collected).
IVM can be used as an alternative for these women. In this treatment little or no ovarian stimulation is required and the eggs are collected from the ovary when they are small and quite immature. The eggs are then placed in special culture solutions in the laboratory to mature. Once matured they can be fertilised and developed to suitable stage embryos for transfer back to the uterus.
This is also a technique that can be used for women to freeze eggs or embryos prior to embarking on chemotherapy for breast cancer as they may want to limit the ovarian stimulation performed.
There are certain situations where it may be advantageous to know part of the genetic make-up of the embryo prior to deciding to transfer it back to the uterine cavity. The patient is treated using IVF and when the embryos are three or five days old, one or more cells are extracted (“embryo biopsy”) and tested for either specific genes or a variety of chromosomes. The two types of genetic testing can be summarized as follows:
PGD: A number of people in the population carry genes on their chromosomes that may result in a miscarriage or an affected child. Such diseases may include cystic fibrosis, muscular dystrophy, Fragile X syndrome and thalassaemia. In these instances we can identify whether the affected gene is present in an embryo prior to implantation;
PGS: Certain patients may be at a higher risk of a chromosomally abnormal embryo. These include:
- women who are ≥ 35 years of age; or
- patients who have had ≥ 3 failed IVF attempts; or
- women who have had ≥ 2 miscarriages; or
- patients where it is known that there are unbalanced chromosomes
In these instances we can assess the normality of eight chromosomes (those most likely to be identified in miscarriage material) and implant an embryo which is normal for these.
PGD and PGS are regulated by law in Western Australia and may only be used in particular instances. This can be discussed with you at the centre.
There are instances where embryo development occurs entirely normally in the laboratory, however the embryo does not implant to form a pregnancy. This may be due to the embryo not being able to escape from its shell (zona pellucida), genetic anomalies or uterine/maternal disorders.
In the first of these (i.e. embryo not able to escape from its shell), it may be due to either a thickening or hardening of the zona pellucida. This in turn may be due to advanced maternal age or elevated FSH (follicle stimulating hormone). If this is a likelihood the scientist in the laboratory can place a small hole in the zona pellucida using a finely directed laser beam. This will allow the embryo to “hatch” out from the zona pellucida after reaching the appropriate stage (expanded blastocyst).
Sperm can be frozen quite successfully in a special solution and stored in secure liquid nitrogen vessels. Under Western Australian law, the sperm can be stored for a maximum of 15 years and cannot be used for treatment posthumously. Our laboratory is able to provide this service for the following instances:
- Male partner not available on the day of the woman’s treatment;
- The male partner has declining or fluctuating sperm counts;
For testicular sperm (where it is often inconvenient to schedule a TESA/testicular biopsy on the same day as the woman’s egg collection)
During an IVF cycle there are often a number of eggs collected and a number of good quality embryos generated. We will normally transfer one suitable embryo. Therefore any remaining embryos can be frozen and stored for subsequent treatment.
Our laboratory is able to freeze the embryos by traditional “slow” methods or by ultra-quick vitrification. The success of the freeze-thaw procedure is generally around 70%, but depends on the stage of embryo freezing and the methods used.
Under Western Australian law embryos can only be stored for a maximum of 10 years. Also, a patient is unable to proceed to a fresh IVF attempt if the are three or more embryos in storage.
The technology of oocyte freezing was first developed in the mid-1980’s. However, due to poor results, very few centres have offered this technique to patients. Recent advances have demonstrated improved success rates. However, the survival post-thawing, along with subsequent pregnancy rates are still lower than that of embryo freezing.
Despite this, there are a number of instances where it may be more appropriate to freeze oocytes, rather than embryos:
- For ethical reasons, the freezing of embryos is unacceptable for some patients;
- Women who are young but are commencing ovarian failure. If the woman does not have a partner, then the only acceptable choice is to freeze oocytes;
- Women who are about to undertake cancer therapy that may render them infertile. In single women this is probably a more acceptable technique than freezing slices of ovarian tissue.
IVM technology can also be used for this group of women. In cases of cancer that are estrogen sensitive, it may be more advisable to retrieve immature oocytes without ovarian stimulation and freeze the oocytes once mature;
- Cases where the male partner is unable to provide a semen sample on the day of egg collection.
As with the freezing of sperm, we are only able to store the oocytes for 15 years and are unable to use the oocytes in treatment posthumously.