In IVF/ICSI cycles, the progesterone levels induced by ovarian stimulation are low, therefore the luteal phase is supported by progesterone. The use of progestogens in IVF is associated with an improvement in the live birth rate Standard protocol for luteal phase support has not yet been established. Currently vaginal progesterone is widely used, since the classic oral progesterone seems to result in a low bioavailability and a lower pregnancy rate. However, vaginal administration of progesterone is associated with vaginal irritation, discharge and bleeding. For all these reasons, there is a need for an effective, well tolerated, and safe treatment that can improve patient satisfaction and compliance.

Many studies have observed similar pregnancy rate results with dydrogesterone and micronized vaginal progesterone. A new RCT including a total of 1143 patients by Tournaye, showed that dydrogesterone treatment had a similar safety profile to micronized vaginal progesterone (MVP) for luteal support as part of ART treatment. The crude pregnancy rates at 12 weeks were 37.6% and 33.1% in the dydrogesterone and MVP treatment groups respectively.

Regarding the administration route of progesterone, intramuscular and transvaginal routes are the two conventional progesterone administration techniques. However, very few studies have compared the advantages of oral dydrogestrone with vaginal progesterone for luteal support in ART cycles.

The objective of the investigator's study is to demonstrate the superiority of oral dydrogesterone (Duphaston) 10 over MVP (Utrogestan) used for luteal supplementation in cryo-warmed embryo transfer cycles. Upon consent, 224 patients women will be randomly allocated into either one of the study groups using a simple randomization method by computer-generated random numbers. Group I will receive the oral dydrogesterone, while group II will receive the vaginal microprogesterone.

Inclusion Criteria:

• Normal uterine cavity
• Normal Hormonal investigation: TSH,PRL,FBS
• Frozen embryo transfer cycles: at least 2 embryos
• Primary or secondary infertility: tubal occlusion, male factor, unexplained, endometriosis, ovarian factors…
• Body mass index (BMI) ≥18 to ≤30 kg/m2

Exclusion Criteria:

• Preexisting untreated medical condition (thyroid disease, diabetes mellitus, hypertension, pulmonary conditions, cardiac condition…)
• History of three or more consecutively failed In Vitro Fertilization (IVF) cycles after embryo transfer
• History of three or more miscarriages
• Previous allergy reactions to progesterone products