To describe AMH serum levels dynamics during natural cycle using an automated assay.

The potential benefit would be using an automated assay for AMH, the dynamics of serum levels during the natural cycle and to check the inter-cycle variations.

Because of the many clinical decisions that are based on AMH levels alone the results of this study could bring reassurance to the continuous use of AMH in daily practice. More importantly, no studies to date have been performed on the newer automated assays evaluating variability of AMH levels.

Inclusion Criteria:

• Women with written informed consent.
• Women between ≥ 18 and ≤ 37 years of age.
• BMI between 18 and 28.
• Normal physical examination and pelvic exam.

Exclusion Criteria:

• Pregnancy.
• Breastfeeding.
• History of any disease/iatrogenic intervention which could have had an impact on the ovarian reserve (e.g. ovarian surgery, chemotherapy, radiation of the pelvis, endometriosis)
• Intake of OCP for the two last menstrual cycles.

Healthy women.

Healthy women with regular menstrual cycles.