1. Women with known uterine malformations or significant myomas 2. Women with elevated Progesterone of at least 1.5 ng/mL for the duration of more than 72 hours before embryo transfer can be performed 3. Women suspected of having endometrial pathology based on previous treatment cycles i.e. "thin endometrium", polyps, adhesions 4. Women whose embryos did not survive the thawing process, i.e. no embryos available for transfer after thawing 5. Women without follicular development