Implantation Window (IW)

Implantation window is a diagnostic test that utilizes Next-Generation Sequencing technology to evaluate your endometrial receptivity status.

What is Implantation Window (IW)?

Implantation Window (IW) is a diagnostic test that utilizes Next-Generation Sequencing technology to evaluate your endometrial receptivity status.Endometrial receptivity is defined as the optimal time where the endometrial is most receptive to implantation; therefore, identifying the ideal embryo transfer time to increase the chances of a successful pregnancy.

IW compares your expression profile for a panel of 323 genes that have been identified as a signature for endometrial receptivity.This test is a highly sensitive and specific, allowing a personalized implantation window to be determined for each patient.

To achieve pregnancy, an embryo should successfully attach to the uterine lining at a time in which the uterus is ready (receptive). This time period, or window, lasts approximately 2-5 days per month. Hormonal regulation and genetics play a crucial role in preparing the endometrium and implanting the blastocyst. Lack of synchronization between the time of implantation and endometrial receptivity could lead to an unsuccessful pregnancy.

Why did we develop IW?

In-vitro fertilization (IVF) remains the most powerful tool to date to achieve pregnancy in infertile couples; however, implantation failure is a common occurrence.

Chromosomal abnormalities are the leading cause of over 60% of IVF failures which could be examined by aneuploidy screening. Approximately 15% of IVF failures are due to miscellaneous reasons that include poor embryo quality and congenital or acquired uterine malformations.

Another major factor, which accounts for about 25% of IVF failures, is the lack of synchronization between endometrial responsiveness and embryo implantation. Implantation Window is a test that overcomes this limitation by predicting a women's ideal endometrial receptivity. This allows for personalized embryo transfer, increasing the chances for a successful outcome.

Who should use the IW test?

The test is recommended for patients who have experienced recurrent implantation failure despite having euploid embryos with optimal morphology. In addition, patients should have a morphologically normal uterus and endometrial thickness.

How does it work?

An endometrial biopsy is collected and evaluated for its receptivity status at that given time. This biopsy is usually collected on Luteinizing Hormone (LH) Day LH+ 7 if on a Natural cycle, or Day progesterone+ 5 following Progesterone stimulation if on a Hormone Replacement Therapy (HRT) cycle.

Based on our analysis, your gene expression profile determines whether your endometrium is:

  • Receptive: Your gene expression profile is associated with a receptive state for implantation; therefore, it is the optimal period of implantation.
  • Pre-Receptive: Your gene expression profile is associated with a pre-receptive state for implantation; this is potentially indicative of a displaced window of implantation. Earlier administration of progesterone or an increase in the duration of progesterone treatment by 1-2 days is recommended. A new biopsy will be taken using this treatment cycle to confirm your optimal IW.
  • Post-Receptive: Your gene expression profile is associated with a post-receptive state for implantation; this is potentially indicative of a displaced window of implantation. A 1-2 day delay in progesterone administration is recommended. A new biopsy will be taken using this treatment cycle to confirm your optimal IW