To evaluate the correlation between cycle day determination by clinical signs, study participant testimony, endometrium histopathology biopsy and ex-vivo imaging of the uterus endometrium.

In order to assess the efficacy of using ex-vivo endometrial imaging to determine optimal time for embryo transfer, two to four separate analyses, including imaging, and the current standard method of endometrial dating (ultrasound, histological and blood tests) will be performed as well as participant's testimony. Dating by hormonal profile (blood tests) will be contingent on availability of the tests for each subject. So shall be the ultrasound test. During the analysis data will be acquired for subsequent correlation analysis. In addition, a parallel in-vivo analysis, similar in methodology to the ex-vivo analysis, may be performed via imaging by hysteroscopy.

Inclusion Criteria:

1. Gender: Female

2. Age: 18-40

3. Belong to one of the three following groups:

   1. Women undergoing fertility treatment, and are regularly ovulating
   2. Women whose fertility status is unknown
   3. Women proved to be fertile (previous spontaneous successful pregnancy)

Exclusion Criteria:

1. Women with known existing endometrial pathology
2. Women with known history of infertility due to oligo-ovulation or anovulation.
3. Women with medical history of malignant tumors in their reproductive system
4. Women that are on any hormonal medications or treatments (excluding hormonal contraception in previous cycles)
5. Women that are on hormonal contraception treatment in their current cycle
6. Women with intrauterine device
7. Women menstruating on the day of the biopsy collection

Females

The study will include up to 200 women between the ages of 18 - 40, to be recruited from the general population and medical center patient population, after determination that they are suited to the study according to the inclusion/exclusion criteria, and after having given informed consent to participate in the study.

The sample size of the study will be determined such that adequate mapping of the 24 days of the menstrual cycle (putting more weight on luteal phase), excluding menstruation days (assuming a 28 day cycle), and dividing of the cohort into subgroups by age, can be achieved using the study methods described below, while adhering to financial constraints.