Last reviewed · How we verify
NCT05215119: FET
Immediate Versus Delayed Natural Cycle Frozen Embryo Transfers
trial testing natural cycle endometrial preparation in Clinical Pregnancy in 818 participants. Completed in 8 February 2025.
8 February 2025
Quick facts
| Lead sponsor | Antalya IVF |
|---|---|
| Status | Completed |
| Study type | OBSERVATIONAL |
| Enrollment | 818 |
| Start date | 4 March 2022 |
| Primary completion | 8 February 2025 |
| Estimated completion | 8 February 2025 |
| Sites | 1 location across Turkey (Türkiye) |
Drugs / interventions tested
- natural cycle endometrial preparation
Conditions studied
- Clinical Pregnancy — all drugs for Clinical Pregnancy →
Sponsor
Antalya IVF — full company profile →
Who can join
Adults 18 to 40, any sex, with Clinical Pregnancy. Patients with the condition only — healthy volunteers not accepted.
Sponsor's own description
Introduction: Based on recent studies the suggestion is that natural cycle frozen embryo transfers (NC FET) should preferably be used, with evidence suggesting that artificial cycle FET (AC FET) is subject to increased risks of adverse obstetric and perinatal outcomes and possibly lower live birth rates. There, however, is limited evidence on the most efficient and effective timing of NC FET following oocyte retrieval. Objective: In this non-inferiority randomised controlled trial, the effect on reproductive outcomes of NC FET performed immediately following the oocyte retrieval cycle (i.e., after one menstruation) will be investigated. Materials and Methods: At a single IVF centre, patients will be recruited from infertile patients presenting for freeze-all-IVF treatments. Patients aged 18 to 30 years will be enrolled, if they had ≤2 previous embryo transfers and had ≥1 blastocyst cryopreserved in their freeze-all cycles. Enrolled patients (N = 800) will be randomised (1:1) to either the immediate group (i.e., FET performed in the menstrual cycle immediately following the oocyte retrieval cycle) or the delayed group (i.e., FET performed in the menstrual cycle following two menstruations). All FET will be performed in NC. The primary outcome measure will be clinical pregnancy, defined as the visual confirmation by transvaginal ultrasound scan of a gestational sac with normal heartbeat at \>5 weeks of gestation. The analyses will be performed according to per-procedure principles. Results: The ovarian, endometrial and time to transfer outcomes of the immediate group will be compared with those of the delayed group. The clinical pregnancy rate of the immediate group will be compared with that of the delayed group.
Publications & conference data
No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.
Verify or expand the search:
- PubMed search for NCT05215119
- Europe PMC full search
- ASCO Meeting Library
- ESMO Meeting Library
- bioRxiv preprints
- medRxiv preprints
- Google Scholar
Related trials
Other Antalya IVF trials
Trials by the same sponsor.
- NCT04744844 — DNA Amplification in Blastocoel Fluid · NA · terminated
- NCT03095053 — PGT-A Versus Blastocyst Morphology Selection · NA · completed
Verify against primary sources
- ClinicalTrials.gov — authoritative US registry record
- WHO ICTRP — international registry index
- EU Clinical Trials Register
- Sponsor press releases (Google)
- Trial protocol + status: ClinicalTrials.gov NCT05215119 (US National Library of Medicine, public domain)
- Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
- Sponsor: as reported to ClinicalTrials.gov by Antalya IVF
- Last refreshed: 11 February 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT05215119.
Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing