The use of additional treatments, or 鈥楢dd-ons鈥� is regulated by the HFEA and refers to the technologies and treatments listed on the Please visit here for the most up-to-date information on these treatments.聽
About 5-6 days following fertilisation, the developing embryo is ready to implant in the lining of the uterus. Before it can do so, it has to break out of the zona or shell, which has protected it for the first few days of development. This is known as hatching.
There is some evidence from animal studies to suggest that the zona may become hardened when the embryo is cultured outside the body, or when surplus embryos are frozen and thawed.
To counteract this zona hardening, a technique called 鈥渁ssisted hatching鈥� has been developed. This involves the creation of a small hole in the zona, designed to help in the hatching process. This can be done using a laser or using a fine glass pipette. After assisted hatching the embryos are incubated until the embryo transfer, which is carried out as normal.
As with any in vitro procedure, removal of the embryo from the incubator, and its manipulation, carry a risk of damage. 聽In addition, the creation of too large or too small a hole, may damage the embryo. In practice the procedure is very straight forward and the risk of damage to the embryo is negligible.
There is limited evidence providing support for the idea that assisted hatching is of benefit to anybody, especially in a first cycle of treatment. However, a number of small studies suggest that it may benefit the following patient groups:
Embryoglue is a pre-transfer culture medium that contains a substance called hyaluronan, which may improve the chance of the embryo implanting in the womb. Embryoglue is designed to mimic the conditions within the uterus at the time of embryo implantation. It intends to increase the chance of implantation by increasing the viscosity, encouraging attachment to the uterine wall, and increasing enrichment factors thought to sustain the embryo during transfer and implantation. It is important to understand that the mechanism of embryo implantation and the role of hyaluronan is not fully understood, but is theoretical.
In 2020 Cochrane (a not-for-profit, independent research body) reviewed the published results on the effects of increased hyaluronan during embryo transfer and reported that adverse outcomes such as ectopic pregnancy, embryo and foetal abnormalities were reported in both the Embryoglue and non-Embryoglue test groups. It was also reported that increased hyaluronic acid may also result in an increased number of multiple pregnancies.
There is limited evidence providing support for Embryoglue in increasing the chance of pregnancy. Due to this lack of robust evidence, Salisbury Fertility Centre do not recommend the use of Embryoglue. However, we respect patient choice and can provide this upon request. Embryoglue has been suggested to be potentially beneficial in the following patient groups:
When a sperm meets an egg (oocyte), it should trigger a process called egg activation which starts the process of fertilization and embryo development. Failed fertilization of some or all mature eggs following sperm injection (ICSI) could be attributed to failed activation of the eggs. AOA intends to activate eggs after ICSI. AOA could be suggested for patients that have had two previous ICSI cycles with <30% or no fertilisation, patients with total globozoospermia, or when the male partner has PLCzeta deficiency. In these cases, AOA could increase the fertilization rate with ICSI by helping to activate the eggs after the injection procedure.
The procedure for the use of AOA using calcium ionophore is simple; it requires the transfer of injected eggs into the AOA solution for a short culture period.
Egg activation using calcium ionophore theoretically could cause embryos to have abnormal numbers of chromosomes, which may cause the pregnancy to miscarry. Additionally, there have been some concerns that AOA may lead to an increased risk of malformations, and further studies are required to establish if AOA is an effective and safe methods to use in attempts to overcome ICSI failure. Therefore, if this procedure is used, it is important that you understand that safety in terms of the potential developmental consequences and birth outcomes, has not yet been established.
Due to the lack of robust evidence and the criteria recommended in the best practice guidelines, we do not promote the use of AOA in our clinic. However, if, following case review this technique has been suggested to be useful for you then we can accommodate this.
Our staff at 星空无限 have long been well regarded for the quality of care and treatment they provide for our patients and for their innovation, commitment and professionalism. This has been recognised in a wide range of achievements and it is reflected in our award of NHS Foundation Trust status. This is afforded to hospitals that provide the highest standards of care.
