Subcutaneous Progesterone in Frozen- Thawed Single Euploid Blastocyst Transfer.

Inclusion Criteria:

• subject has given written informed consent;

• Premenopausal women 35 to 42 years of age at the time of consent (at least 35 [including day of birthday] and no more than 42 [up to the day before their 43rdbirthday]);

• Valid indication for IVF treatment (i.e. history of infertility according to ASRMdefinition, single women or same-sex couples);

• Consistent, regular spontaneous ovulatory menstrual cycle with normal length (24-38days included);

• Body mass index (BMI) < 38 kg/m2;

• Subject with at least one euploid frozen blastocyst from a previous IVF treatmentcycle;

• Less than 3 previous consecutive euploid blastocyst transfers without a life birth;

• Baseline Follicle Stimulating Hormone (FSH) < 15 mIU/mL, and Anti Muellerian Hormone (AMH) >0.7 ng/mL (within 6 months from screening for subjects requiring astimulation cycle to obtain a euploid embryo); and Estradiol (E2) < 90 pg/mL andProgesterone (P4)< 1.5 ng/mL at Visit 1 (for all subjects);

• Semen used during IVF(for subjects requiring a stimulation cycle to obtain a euploidembryo) was produced by ejaculation (not surgically derived sperm) from either thepartner or from a sperm donor. Donor must be 18-40 years of age at the time ofcollection and compliant with 21 Code of Regulations (CFR) section 1271 Subpart C;

• Hysterosalpingography, hysteroscopy, 3D ultrasound or sonohysterogram documenting anormal uterine cavity within the last year;

• Normal cervical cytology/High Risk human papillomavirus (HPV) testing per AmericanCollege of Obstetricians and Gynecologists guidelines.

Exclusion Criteria:

• Oligo or anovulation (spontaneous menses > 39 days apart);

• Breastfeeding or Pregnancy;

• Contraindication to pregnancy (i.e. an active, uncontrolled clinically significantmedical condition or abnormality of the sexual organs determined by the provider);

• Known family history of major congenital anomalies;

• Moderate to severe current endometriosis (stage 3 or 4);

• Presence of a unilateral or bilateral hydrosalpinx that communicates with theuterus, that has not been ligated prior to treatment;

• Recurrent pregnancy loss (RPL) as defined by the American Society of ReproductiveMedicine (ASRM) as two or more consecutive failed clinical pregnancies;

• Presence of a submucosal or intramural fibroid > 4 cm which distorts the uterinecavity or are > 5 cm in diameter;

• Untreated uterine pathology that could impair embryo implantation (i.e.scarring/Asherman's syndrome or intra uterine polyps > 1 cm in size);

• Type 1 or 2 diabetes mellitus based on American Diabetes Association (ADA)criteria3;

• Uncontrolled adrenal or thyroid dysfunction;

• History of conditions (i.e. toxic shock syndrome) that would contraindicate use of avaginal progesterone product;

• Subjects with hepatic impairment (liver function tests > 2x upper limit of normal);

• Subjects with renal impairment (estimated creatinine clearance <60 mL/min/1.73 m2);

• History of an active or treated autoimmune disease (i.e. systemic lupuserythematosus);

• History of arterial disease (i.e. Prior or active thrombophlebitis, thromboembolicdisorder or known thrombophilia);

• Neoplasias (current) or history of neoplasia that may be responsive to progesterone;

• High grade cervical dysplasia;

• Undiagnosed vaginal bleeding (i.e. at the time of screening);

• Use of donor eggs or plans to use a gestational carrier;

• Use of endometrial receptivity array (ERA) test to postpone or anticipate the embryotransfer (ET) day;

• Use of epididymal, testicular , electro-ejaculated or chemotherapy exposed sperm;

• Known allergy to progesterone preparations or their excipients;

• Current dependence on alcohol, tobacco (must not be smoking/using tobacco x 2 monthsbefore the study) or drugs or psychotropic medications labeled as PregnancyCategories D and X;

• Use of concomitant medications within 1 month previous the start of the FET cyclepreparation up to gestational week 12 that might interfere with the study evaluation (use of insulin sensitizing agents, vaginal medications/preparations, any drugs forluteal support other than those specified in the protocol, aspirin, any hormonaltreatment, with the exception of levothyroxine);

• Participation in a concurrent clinical trial or in another investigational drugtrial within the past 2 months-