It refers to infertile patient who have undergone many IVF cycles and produced good embryos but the embryos have failed to implant for unexplained reason .
1- Transfer of many embryos: Many embryos can be transferred for difficult cases (Except for fertility clinic in UK and Australia where the number of embryos that can be transferred is limited by law).
While transferring many embryos increases the risk of multiple pregnancies, this risk is negligible for difficult cases, and it can be decreased by fetal reduction.
2- Aggressive Superovulation: High dose of HMG is used in order to help patients with a poor ovarian response to grow more eggs to have more embryos to transfer.
3- Difficult embryo transfer: That’s why we do artificial transfer for each patient by inserting a catheter into the uterus to measure its length and depth to know where to insert the embryos.
4- PCOD (Polycystic ovarian disease):For these patients, ovulation induction is done carefully to have an average number of follicles only so we don’t end up by super ovulating them. OHSS is avoided by aspirating each follicle carefully until it collapses completely. In case of any further risk, the embryos are frozen for future use.
5- Chromosomal abnormalities:It has been found that chromosomal abnormalities can be found in 50% of embryos even in good-looking ones.
6- Blastocyst transfer (Rather than transferring them on day 2 or 3) : The rate of blastocyst development is only (30%), therefore it is not the best for patients with repeated implantation failure, especially those who have few embryos available.
7- Immune system (ANA, APL antibodies, NK cells, antithyroid antibodies): Sometimes, an immune system can have a bad effect on an individual by different mechanism and can cause infertility and recurrent pregnancy loss, but abnormal results are often found in normal fertile women as well, and although there is no evidence to suggest that immune therapy will result in successful pregnancy, but we are still considering it in cases of IVF failure.
8- Thrombophilia: Thrombophilia is conditioned that result in an increased chance for clotting of blood. Although it's not yet confirmed that thrombophilia can cause implantation failure, there has been widespread use of the anticoagulant's heparin and aspirin for women with IVF implantation failure with varying results.
9- IMSI (Intracytoplasmic morphologically-selected sperm injection)
IMSI is done by using an extremely high-powered microscope to select the sperm cells with the best morphological quality to be injected into eggs, by magnifying the actual size of the by 8000 times, we can detect the abnormal sperm. Usually, abnormal sperms are identified if they were magnified 400 times their actual size.
Many patients have finally conceived after multiple IVF attempts even though there was no change in treatment protocol in all IVF clinics so sometimes it just needs a bit of luck, patience and perseverance.