An Analysis to Recurrent Embryo Implantation Failure

Several factors may lead to in vitro fertilization (IVF) failure. However, many women who have had a failed cycle will have a subsequent successful cycle (live birth). While not all issues related to IVF failure can be corrected, some issues can be addressed in an effort to reduce the likelihood of another failed cycle. It’s important to understand what factors are involved in each individual situation.

More than 70% of transferred embryos by IVF/ICSI methods fail to be implanted. The causes for repeated implantation failures (RIF) may be reduced endometrial receptivity or other various uterine pathologies, such as thin endometrium, altered expression of adhesive molecules or Immuno-logical factors; whereas genetic abnormalities of male or female individuals, sperm defects, embryonic aneuploidy or zona hardening are other etiologies for implantation failures. Clinically, endometriosis, polycystic ovaries and hydrosalpinx may decrease implantation following embryo transfer due to dual disorders in the quality of embryos or endometrium.

Probable causes and methods of evaluation for RIF patients have been reviewed and the suggested methods for their treatment, including myomectomy, endometrial stimulation, immunotherapy, hysteroscopy, preimplantation genetic screening (PGS), assisted hatching, zygote intra-fallopian transfer (ZIFT), co-culture, blastocyst transfer, cytoplasmic transfer, tailoring stimulation proto-cols, intracytoplasmic sperm injection (ICSI).

Endometrial injury (biopsy or scratch or hysteroscopy) in the cycle preceding ovarian stimulation for IVF has been proposed to improve implantation in women with unexplained recurrent implantation failure (RIF). These analyses compare the effectiveness of endometrial injury versus no intervention in women with RIF undergoing IVF. Endometrial biopsy/scratch or hysteroscopy performed in the cycle preceding ovarian stimulation were included and the primary outcome measure was clinical pregnancy rate. Local endometrial injury induced in the cycle preceding ovarian stimulation is 60% more likely to result in a clinical pregnancy as opposed to no intervention.

The evidence is strongly in favour of inducing local endometrial injury in the preceding cycle of ovarian stimulation to improve pregnancy outcomes in women with unexplained RIF. Some women undergoing IVF treatment fail to conceive despite several attempts with good-quality embryos and no identifiable reason. We call this ‘recurrent implantation failure’ (RIF) where the embryo fails to embed or implant within the lining of the womb. Inducing injury to the lining of the womb in the cycle before starting ovarian stimulation for IVF can help improve the chances of achieving pregnancy.

Injury can be induced by either scratching the lining of the womb using a biopsy tube or by telescopic investigation of the womb using a camera. We performed a collective review of the available good-quality studies that used the above two methods in the cycle prior to starting ovarian stimulation for IVF. Furthermore, scratching of the lining was 2-times more likely to result in a clinical pregnancy compared with telescopic evaluation of the lining of the womb. This study suggests that in women with RIF, inducing local injury to the womb lining in the cycle prior to starting ovarian stimulation for IVF can improve pregnancy outcomes.

Age is a very important factor in the success or failure of IVF. As women age, the number of eggs in the ovaries decrease, and the quality of the remaining eggs lessens. The decline begins in your 30s and increases rapidly after age 37. The chance of a live birth after IVF using fresh, non-donor eggs or embryos is approximately 32 percent for a 35-year-old woman, but only 16 percent for a 40-year-old woman.

Fertility specialists assess the quality of the egg based on the age of the woman, as well as the number of cells in the egg. The fertilized egg (embryo) starts as a single cell and continues to divide until it is multi-celled. Three days after egg retrieval and fertilization, most specialists prefer that some of the embryos have at least 6 or 7 cells. Eggs with fewer cells are less likely to fertilize and the chances of IVF failure increase. In general, the more eggs you produce in a given IVF cycle, the greater your chance that the IVF cycle will be successful.

The ovaries of some women, however, do not develop many follicles because they do not respond to the IVF medication used to encourage the ovaries produce multiple eggs. (One egg develops in each follicle.) You are likely to have poor response to IVF medication if you are older than 37, have elevated FSH levels, or have a reduced number of eggs remaining in your ovaries. IVF is likely to fail if fewer than three mature follicles are produced.

A pregnancy loss or miscarriage after IVF may be due to problems related to the uterus, such as polyps or fibroids. Many fertility specialists, however, believe that most implantation failures are due to the seize of the embryo; in other words, the embryo stops growing. This may be the result of a genetic defect that interferes with the embryo's development.

A pregnancy loss or miscarriage after IVF may be due to problems related to the uterus, such as polyps or fibroids. Many fertility specialists, however, believe that most implantation failures are due to the arrest of the embryo; in other words, the embryo stops growing. This may be the result of a genetic defect that interferes with the embryo's development.