The current study is conducted at Assisted Reproduction Unit at Almana general Hospital, kingdom of saudi arabia.and other private centers in Egypt. The study protocol was approved by the Local Ethical Committee. The study aimed to include women suspected to be at high risk for development of OHSS during agonist ovarian stimulation protocol.The study includes only women of couples singed written consent to participate in the study, to undergo embryo freezing and to postpone for transfer of cryopreserved embryo.