This is one of the simplest fertility treatments we offer at the Trinidad & Tobago IVF & Fertility Centre. Ovulation induction and timed sexual intercourse is offered to couples when the sperm analysis is normal, ovarian function appears normal and we do not suspect obstruction of the Fallopian tubes. We usually help you to produce 2-3 follicles using tablet medication (usually called Clomiphene). Once we assess that the eggs are ready, we induce ovulation and advise you when to have intercourse. A pregnancy test is then performed about 2 weeks afterwards.
Intrauterine Insemination (IUI) is the placing of concentrated fast moving sperm into a womb. The sperm is prepared by an embryologist an hour or two before the IUI treatment. The final sample is placed near to the top of the uterine cavity, using a fine tube (catheter) passed through the cervix. The fast-moving sperm then have a shorter distance to swim to reach the eggs, which are released to meet the sperm. The IUI procedure is performed on an outpatient basis and only takes about 10 minutes to complete.The growth of the egg follicles will be monitored using regular ultrasound scans in the few days just before programmed ovulation.
Intra Cytoplasmic Sperm Injection (ICSI) is a procedure by which a single sperm is injected into an egg. If the sperm sample is assessed as having normal parameters for count, movement and shape, then In Vitro Fertilization (IVF) is performed. If the sperm sample shows sub-optimal parameters, there is a risk of failure to fertilise with conventional IVF, so ICSI is recommended.
Indications for ICSI:
ICSI involves selection of sperm by a specialist ICSI practitioner, and is a purely laboratory-based procedure. Using a high-powered microscope the ICSI practitioner is able to select a sperm with the best chance of causing fertilisation. After manipulation and immobilisation of the sperm, it is aspirated into a very fine glass needle with a very sharp tip. This needle is one tenth the size of a human hair. The needle is then carefully inserted into the egg at an exact position in order not to cause any damage to the egg itself. The immobilised sperm is then injected into the cytoplasm of the egg (ICSI) and the needle carefully removed.
Throughout the ICSI procedure, the egg is held in place with a separate pipette to ensure no movement or consequent damage during the ICSI procedure.
After the ICSI procedure, the eggs are placed in their culture dish and assessed the following day for fertilisation.
Surgical Sperm Retrieval (PESA &TESA)
Two additional procedures may be used in specific cases of male factor infertility and are normally used in conjunction with ICSI. These are PESA (Percutaneous Epididymal Sperm Aspiration) and TESE (Testicular Sperm Extraction). These procedures are used when no sperm are found in the ejaculate and surgical retrieval of the sperm is necessary.
PESA and TESE are carried out under sedation and are normally performed before the female partner’s eggs are collected. We recommend freezing surgically retrieved sperm in advance to ensure sperm are available to perform ICSI.
Controlled Ovarian Stimulation
Controlled Ovarian Stimulation aims to increase the number of eggs produced by your ovaries. One of our fertility specialists will prescribe a fertility medication and monitor how the follicles containing eggs grow. When the follicles reach a suitable size you are ready for egg collection.
The egg collection is performed under ultrasound guidance using anaesthesia and takes around 20 minutes. All your follicles are emptied using specialist equipment and the embryologist immediately checks the collected fluid for the presence of eggs. Once the eggs are found they are placed in a special culture medium.
Fertilisation and Culture
The sperm sample is carefully prepared and washed, so that 100,000 fast moving sperm are introduced to the same culture as the eggs. These are left together in apetri dish in an incubator overnight for the sperm to fertilise the eggs.
The next day (day 1) the eggs are examined for signs of fertilisation. Fertilised eggs are cultured in their own specific dish. On day 2 we expect to see a dividing embryos. Not all embryos are able to make a baby, so the embryologist has to select the best quality embryo(s) for the embryo transfer procedure.
The embryo Transfer procedure completes the whole IVF treatment. During an embryo transfer the best quality embryo(s) is gently placed into the patient’s womb using special, flexible catheter. The procedure is performed using ultrasound scanning to ensure the correct positioning of the catheter within the womb. The embryologist places the embryos in the catheter, and the clinician carefully introduces the catheter through the uterine cervix into the womb. The embryo(s) is then gently placed into the womb to further develop and implant. The whole procedure takes about 10 minutes, and is performed on an outpatient basis without anaesthesia.
During IVF the embryo transfer often takes place on day 2 or 3 following the egg collection. At this time, the embryos are at the 2 - 8 cell stage of development. It may be difficult for the embryologists to accurately select which embryos have the best chance of forming a pregnancy at such an early stage of their development.
What is a blastocyst?
A blastocyst is a highly developed embryo. The embryo usually reaches this advanced stage of development on day 5 following the egg collection. This means the embryo has divided many times into a large number of cells whilst in the embryology laboratory. At this stage it is nearly ready to attach to the wall of the uterus (implantation).
Blastocysts look very different compared to embryos at earlier stages of development. At the blastocyst stage, the embryo is now made up of two very different types of cells and a central fluid filled cavity. The surface cells lining the inside of the shell (called the trophectoderm) will become the placenta, and the inner cells (called the inner cell mass) will become the baby.
What are the advantages of blastocyst transfer?
Whilst the majority of fertilised eggs will develop into a 4-cell embryo, only about half of these embryos will develop into the blastocyst stage. Therefore, blastocysts are considered to be a more “select” group of embryos with a higher chance of implantation. Because they are more likely to form a pregnancy, we can transfer fewer without reducing the chance of pregnancy.
What are the disadvantages of blastocyst transfer?
It is possible that an IVF cycle will not result in a transfer of any embryos if none of the 2-day-old embryos develop into blastocysts. In this situation, the IVF cycle will be abandoned before that transfer stage
Which patients will benefit from blastocyst transfer?
We are currently suggesting that blastocyst transfer be considered by those patients who have a large number of embryos. However, we will consider offering this treatment to any patient following discussion with one of our fertility specialists. However, blastocyst transfer will probably not benefit patients who only have only a few embryos.
Embryo freezing by vitrification may be performed in couples who have just received a fresh embryo transfer procedure and have good quality embryos remaining which were not transferred. The vitrified embryos can be kept in storage to be used in the future.
An advantage of vitrification is that eggs, embryos and blastocysts can be ‘stored’ in liquid nitrogen for future use.
Vitrification is the process whereby the solution containing the embryos is cooled so quickly that they instantaneously solidify into glass-like structures. This increases the survival rate of the embryos when they are warmed.
Avoidance of ice-crystal formation is one of the main aims of successful embryo cryopreservation. If water becomes trapped inside an embryo, ice crystals form during the cooling process, which may damage the cell. However, vitrification prevents the formation of ice crystals by adding highly concentrated cryoprotectant solutions and cooling the cells at an extremely rapid rate.