Maximise your Chances of Conception

Blastocyst Embryo Transfer is a specialised IVF technique in which an embryo that has been cultured to the blastocyst stage is transferred to the womb.

It is at the blastocyst stage of development (five days after fertilisation) that an embryo would normally move out of the fallopian tube and into the uterus. Once in the uterus, the blastocyst starts to attach to the uterine lining in a process known as implantation.

The advantage of attempting to grow embryos to the blastocyst stage is that they should have a greater chance of implantation because their stage of development matches the uterine environment. As a result, fewer embryos can be replaced, which will minimise the risk of a multiple pregnancy.

The disadvantage of trying to grow embryos to the blastocyst stage is that fewer will “survive” or grow to this phase (probably about 30-50%). There is a possibility (up to 10%) that none will reach the appropriate blastocyst stage and therefore, no embryos will be available for transfer. The availability of “extra” embryos for freezing is also significantly reduced.

People who have had unsuccessful attempts with IVF or IVF-ICSI despite having many good-quality eggs retrieved are being offered blastocyst culture as an alternative treatment. couples/individuals with multiple good-quality embryos on day 3 are also good candidates for blastocyst culture. The ability to select the most viable embryos for transfer and implantation should improve their chance of achieving a pregnancy.

Illustrated Guide

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Embryo transfer media are specialised embryo cultures in which a glycoprotein named hyaluronan is used to assist the embryo to implant into the uterus during IVF.

For pregnancy to occur, the developing embryo must implant into the lining of the uterus (endometrium). Research shows that hyaluronan plays an important role in assisting embryos to implant. Hyaluronan is a naturally occurring substance found in the uterine cavity and fallopian tubes.

The embryos selected for transfer are placed in a small amount of hyaluronan. When the transfer takes place, the embryos are loaded into a catheter along with the hyaluronan and released into the uterus. The transfer medium does not guarantee implantation but may assist it.

There is some evidence to suggest that those aged over 38 show the most benefit, with a significant increase in pregnancy rates when a transfer medium with hyaluronan is used (Balaban et el., 2004). There have also been studies that indicate frozen/thawed embryos may have increased pregnancy rates through the use of a hyaluronan transfer medium.

Assisted hatching is a scientific IVF technique that may improve the implantation of embryos into a  uterine lining by creating an opening through which the embryonic cells can hatch out. Pregnancy cannot occur unless the embryo hatches.

Just before embryo implantation, the developing embryo must “hatch” out of its outer shell (zona pellucida). Some embryos seem to have a thicker shell that may decrease their ability to hatch, and therefore reduce the likelihood that they will implant. This may be due to age or other, unknown reasons.

The unfertilised egg is surrounded by the zona pellucida membrane. The zona pellucida ensures that only one sperm cell enters and fertilises the egg. After fertilisation, the embryo begins to cleave into a two-cell, then a four-cell and so on. It is at this early cleavage stage that assisted hatching can be performed.

It has been shown that people older than 37 have a tendency to produce oocytes with a harder and/or thicker zona pellucida than those that are younger. The same goes for individuals with a high level of Follicle Stimulating Hormone (FSH).

The problem of a harder zona pellucida is that the embryo may not hatch and thus not attach to the womb. It has been reported that up to 75% of normal embryos may never hatch. Laboratory procedures involved in IVF may add to the hardening of the zona, as the embryo is not continually exposed to the enzymes present in the natural environment of the fallopian tubes.

There is also evidence to suggest that the process of freezing and thawing embryos may cause the zona to harden, and using assisted hatching can be beneficial.

We offer laser-assisted hatching, which is a gentle and safe way to weaken a small section of the zona pellucida – allowing the embryo to hatch. Several studies have shown that using a laser is superior to chemical and manual hatching. Laser-assisted hatching has several advantages, including minimal handling of the embryo and delivering fast and exact control over the drilling of the hole.

Laser-assisted hatching is performed by the scientists before the embryos are transferred back to the uterus.

There are two methods of genetic testing: Preimplantation Genetic Testing for Aneuploidy (PGT-A) and Preimplantation Genetic Testing for Monogenic/Single Gene Defect (PGT-M)

PGT-A is generally used to detect anomalies in the number or structure of the chromosomes of embryos. PGT-A identifies affected embryos as they are developing in the laboratory before being transferred back to the patient’s uterus during the IVF cycle, in order to improve the chances of pregnancy. If you would like further information, please talk to your treating specialist.

PGT-M is advanced single-gene testing suitable for people who have a family history of a single-gene disorder and are at risk of producing embryos affected by that condition.PGT-M allows testing for disorders including: Cystic fibrosis, Beta-thalassaemia, Thalassaemia, Spinal Cerebral Atrophy and Spinal Muscular Atrophy, BRCA1/BRCA2 (hereditary breast and/or ovarian cancer)