Predictors of Pregnancy Rate in Assisted Reproductive Technology According to Actual Guidelines

Inclusion Criteria: * Female, age ≥ 18 years * Prescribed Duphaston® according local marketing authorization and international and Russian In Vitro Fertilisation guidelines for luteal phase support as part of an Assisted Reproductive Technologies (1 tablet 3 times a day starting at the day of oocyte retrieval) * Elective single embryo transfer in fresh cycle * Normal ultrasound at enrollment without evidence of clinically significant abnormality consistent with finding adequate for Assisted Reproductive Technologies with respect to uterus and adnexa (incl. no hydrosalpinx or clinically relevant uterine fibroids) * Signed the Patient Authorization for Use/Disclosure of Data Exclusion Criteria: * Evidence of cardiovascular, respiratory, urogenital, gastrointestinal/hepatic, hematologic/immunologic, HEENT (head, ears, eyes, nose, throat), dermatologic/connective tissue, musculoskeletal, metabolic/nutritional, endocrine, neurologic/psychiatric, allergy, recent major surgery (\< 3 months), or other relevant diseases as revealed by history, physical examination and/or laboratory assessments which could limit participation in or completion of the study * Acute urogenital disease * Known allergic reactions to dydrogesterone or other progestogens products * Any contraindication or other condition that precludes use of dydrogesterone in a particular patient, in accordance with the precautions listed in the locally approved label (Instructions for the medical use of Duphaston®): * Hypersensitivity to dydrogesterone or any of the excipients * Diagnosed or suspected progestogen-dependent neoplasms (e.g., meningioma) * Undiagnosed vaginal bleeding * Hepatic impairment associated with acute or chronic, current or past liver diseases (as long as liver function tests have failed to return to normal) * Presence or history of malignant liver tumors * Galactose intolerance, lactase deficiency, glucose-galactose malabsorption syndrome * Breastfeeding. * Presence or history of porphyria * Age below 18 years, since safety and efficacy in adolescents aged below 18 years have not been established * Spontaneous abortion (miscarriage) or missed abortion in luteal-phase support as part of assisted reproductive technology * Participation in any other clinical trial within 30 days prior to program start * Mental disability or any other lack of fitness, in the Investigator's opinion, to preclude subjects in or to complete the study * Current or recent substance abuse, including alcohol and tobacco (Note: Patients who stopped tobacco usage at least 3 months prior to screening visit would be allowed) * History of prior chemotherapy * Usage of other progestogens except dydrogesterone * Contraindication for pregnancy * Refusal or inability to comply with the conditions of this program for any reason, including scheduled clinic visits and laboratory tests. * Gestational surrogacy, oocyte or embryo donation