Luteal Support in Artificial Vitrified/Warmed Cycles With Low Progesterone

Inclusion Criteria: * Informed consent form (ICF) dated and signed * Age ≥ 18 and \< 43 years old * Body Mass Index (BMI) ≥ 18.5 kg/m2 and \< 35 kg/m2 * Less than 4 previous Assisted Reproductive Technologies (ART) cycles * Current pregnancy wish * Patients undergoing a single vitrified/warmed single transfer in an artificial prepared endometrium cycle (IVF or ICSI) Exclusion Criteria: * Simultaneous participation in another clinical study * Previous participation in this study * Known reasons for impaired implantation (specifically: presence of a hydrosalpinx; presence of a type I, II or III fibroid; Asherman's syndrome; uterine malformations, intrauterine adhesions, ≥ grade 3 endometriosis according to the ASRM classification, endometrial tuberculosis) * Repeated miscarriages (\> 2 miscarriages) * Untreated and uncontrolled thyroid dysfunction * Tumors of the ovary, breast, uterus, pituitary or hypothalamus * Abnormal vaginal bleeding without a known/diagnosed cause * Ovarian cysts or enlarged ovaries * Fibroid tumors of the uterus incompatible with pregnancy * Malformations of the reproductive organs incompatible with pregnancy * Previous antibiotic hypersensitivity reactions (streptomycin and/or neomycin) * Risk factors for thromboembolic events, such as a personal or family history, severe obesity or thrombophilia * Active smoking * Ongoing pregnancy * Use of carbamazepine, rifampicin or phenytoin * Those unable to comprehend the investigational nature of the proposed study