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Personalized pre- and post-test counseling support

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Implantation Window Test

Implantation Window (IW) is a genetic test that identifies the optimal time for embryo transfer to the uterus during IVF. The test evaluates endometrial receptivity status which is the exact time where the endometrial lining is most receptive to implantation. Identifying the ideal embryo transfer time increases the chances of a successful pregnancy.

When is IW testing offered?

IW testing is recommended for women who have experienced recurrent implantation failure (having had two or more unsuccessful embryo transfers during IVF, despite having euploid embryos with optimal morphology).

How is the test performed?

The test is important for cases where recurrent implantation failure may be attributed to an unpredictable or displaced Window of Implantation (WOI), that may be taking place either earlier or later than predicted. About 25% of IVF failures are due to a lack of synchronization between endometrial responsiveness and embryo implantation. Therefore, IW testing can help overcome this limitation by allowing for a precisely timed embryo transfer, hence increasing the chances for a successful outcome. For patients to properly utilize the Implantation Window test, they should have a morphologically normal uterus and endometrial thickness.

Based on the genetic analysis, IW results are reported and interpreted as follows:

  • Pre-receptive: The endometrium is still not ready to receive an embryo. In such cases, the embryo transfer is recommended to take place later than the time when test was performed.
  • Receptive: endometrium is in the optimal receptive stage and embryo transfer is recommended at the same time at which the biopsy was performed.
  • Post-receptive: The endometrium is beyond the optimal stage of embryo receptivity. Embryo transfer is recommended to take place earlier than the time at which the biopsy was taken.
  • Non-receptive: The endometrium is non-receptive. In such cases the physician will discuss the different treatment options.
Pre-receptive or post-receptive IW results indicate that the embryo transfer schedule needs to be adjusted by the physician through clinical hormonal administration.