Recurrent Implantation Failure (RIF)
Definition - What does Recurrent Implantation Failure (RIF) mean?
Recurrent implantation failure (RIF) is the repeated inability to achieve a clinical pregnancy after numerous attempts at embryo transfer. Specifically, this term typically refers to women under the age of 40 who have not achieved a successful pregnancy after 3 cycles of in vitro fertilization (IVF) and the transfer of at least 4 high-quality embryos. Recurrent implantation failure is a significant cause of IVF failure.
FertilitySmarts explains Recurrent Implantation Failure (RIF)
When an embryo implants into the uterine wall the developing placenta begins to release human chorionic gonadotropin (hCG). This is the hormone that is detected by pregnancy tests. The embryo then further develops and forms a gestational sac, which is visible by ultrasound at around 5 weeks of gestation. Implantation is considered to be successful when both hCG is detected in blood or urine samples from a woman's body and the gestation sac of the developing embryo has been visualized. Successful implantation as confirmed by the presence of both these factors is known as a clinical pregnancy.
Implantation failure is used to describe two different situations. In the first, there has been no evidence of implantation (no hCG was detected). In the second, there was evidence that the implantation process began (hCG was detected) but it did not progress to the point of gestational sac development as visualized on an ultrasound.
Implantation failure may be due to problems with the embryo or the endometrium of the uterus. Embryos may not successfully implant if they are of poor-quality or contain genetic abnormalities. Problems with the uterus leading to implantation failure include fibroids, adhesions, and adenomyosis.
Individuals or couples experiencing RIF will likely undergo several tests to determine the underlying cause. Usually, RIF results from a problem with the uterus preventing implantation. As a result, most tests focus on assessing the uterus for abnormalities. Treatment of RIF is based on the underlying cause. Surrogacy is an additional option.
RIF is a subgroup of recurrent IVF failure. Recurrent IVF failure refers to the lack of successful pregnancy after several attempts of IVF and is often due to poor response to ovarian stimulation. In contrast, RIF specifically refers to the failure to achieve pregnancy due to a lack of successful implantation.