 Approved study subjects will undergo standard controlled ovarian hyperstimulation COH. Protocols and their corresponding medications will be decided upon at the discretion of the treating physician. These may include long gonadotropin-releasing hormone GnRH agonist protocol and GnRH antagonist protocol. Follicular aspiration will be performed in the IVF unit via transvaginal needle aspiration. Endometrial preparation and luteal phase support will be recommended as per our departmental protocol. The number of embryos for transfer will be defined prior to cycle initiation, according to The Israel Society of Obstetrics Gynecology. 