This technique involves the multiple aspiration of the man's testicular tissue with the objective of identifying, and where necessary freezing, motile sperm that will subsequently be used to carry out the assisted reproduction techniques.
If there is no sperm in the ejaculate (obstructive or secretory azoospermia). If it is impossible to obtain a sample of sperm.
In some patients it is the only way to retrieve sperm.
Extended embryo culture up to 5 days
Using the conventional technique, the embryo transfer is carried out two or three days after the egg collection (since they cannot spend more time in the growth medium). Using this new technique, the embryos obtained are kept in the incubators for a longer period of time. Like that, only the good quality, suitable embryos will continue to develop to the blastocyst stage.
Cases in which several transfers of good quality embryos were carried out, everything appeared to have gone well, but a pregnancy was not achieved.
Fewer embryos are transferred, which minimises the risk of multiple pregnancy, but with a higher development potential, thereby increasing the chances of pregnancy. Several studies have shown that embryos in the blastocyst stage are more likely to implant than embryos of 48 to 72 hours.
If none of the embryos reaches the 5th day of development, there may be no embryos to transfer.
This technique is complementary to the In Vitro Fertilisation processes and involves thinning and making a small opening in the shell (zona pellucida) surrounding the embryo, thereby helping it to "hatch" out of the shell and improving its likelihood of implanting in the uterus.
- Older women with high levels of FSH.
- Highly fragmented embryos or embryos with a thicker zona pellucida.
- If several In Vitro Fertilisation attempts have failed.
Aids implantation of the embryo in the maternal uterus.
Transfer of thawed embryos
If the couple has frozen embryos it does not have to repeat the complete In Vitro Fertilisation cycle. The embryos are thawed at the time of transfer to the woman and are transferred in the same way as fresh embryos.
Couples who have already carried out an In Vitro Fertilisation cycle and whose non-transferred embryos were frozen and stored at the time.
In these cases only the last phase of the In Vitro Fertilisation cycle is carried out, which significantly reduces the costs.
The sperm is frozen and stored immersed in liquid nitrogen at a temperature of -196 degrees for the required length of time. When the couple decides to carry out a treatment to try and conceive, part of the frozen sample is thawed and used to achieve fertilisation.
Freezing of samples of sperm is recommended when:
- The male partner has trouble producing a sample of semen.
- The couple wants to be guaranteed the possibility of producing offspring in the event of an accident, death, a vasectomy, or medical treatments involving chemo or radiotherapy which may damage or destroy the man's fertility.
In some cases the embryos do not develop after they have been thawed, which means there is no transfer.