IVF Implantation Failure Implantation failure

IVF Implantation Failure Implantation failure is the failure of an embryo to implant during an IVF cycle.

Some doctors will call failure of a single in vitro fertilization cycle implantation failure. Others maintain that it is not implantation failure until a couple has failed to achieve pregnancy despite several in vitro fertilization failures. Still others look at the total number of embryos transferred as opposed to the number of treatment attempts.

Implantation failure can be divided into three areas:

• Problems with the embryos,
• Problems with the “host uterus” ,
• Problems in the interaction between the embryo and uterus.

What is the best time to transfer embryos in an IVF cycle?

Many IVF programs still perform embryo transfers three days after the egg retrieval. This is known as a cleavage stage or day three embryo transfer. After only three days in laboratory culture, the embryos have typically divided into six or eight cells. It is difficult, at this point in embryo development, to accurately predict which embryos have the best developmental potential.

Some embryos which look great on day three stop developing or develop poorly over the next two days. Alternatively, embryos which didn’t appear to be the best on day three will improve and become very high quality embryos by day five.

Several studies in the past few years have determined that blastocyst transfer is a viable method for improving the chance for IVF implantation. The chance for IVF implantation is higher with a day five transfer than a day three transfer.

Assisted Hatching
Before an embryo can implant in the lining of the uterine cavity, it must first break out or “hatch” from the shell that surrounds it. This allows the embryo to come into direct contact with the cells of the uterine lining. This shell around the embryo is called the zona pellucida. It has been thought by some researchers that IVF implantation may fail in some cases because of the inability of the embryo to hatch out of the zona pellucida. Furthermore, some studies seemed to show that if the hatching process was assisted by creating an artificial opening or thinning of the zona pellucida, the chances for IVF implantation could be increased.


Uterine infection
The inside of the uterine cavity is normally considered to be a sterile environment. It has been strongly suspected that infection of the uterine cavity with bacteria may cause an inhospitable environment that would lead to failure of embryos to implant.


Immune factors as a cause for IVF implantation failure
The immune system is designed to protect individuals from infection with microorganisms and to fight off abnormal processes in the body like cancer. On occasion, the immune system can malfunction and cause harm to an individual through a variety of different mechanisms.

A review of some of the areas that have been looked at follows:

• Anti-phospholipid antibodies (APA)
• Antinuclear antibodies (ANA)
• Antibodies to alpha-2 glycoprotein 1
• Anti-Thyroid Antibodies
• Natural Killer Cells (NK Cells, CD56 Cells)
• Thrombophilias
• Empiric use of anticoagulants for implantation failure

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