Comparative Outcomes of Day 3 and Day 5 Frozen–Thawed Embryo Transfers: A Retrospective Clinical Study


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Kılıç Hamzaoğlu F., DİLBAZ S., ÖZELÇİ R., Kaya O., Utlu Özen E.

Biomedicines, cilt.13, sa.10, 2025 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 13 Sayı: 10
  • Basım Tarihi: 2025
  • Doi Numarası: 10.3390/biomedicines13102412
  • Dergi Adı: Biomedicines
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Directory of Open Access Journals
  • Anahtar Kelimeler: frozen-thawed embryo transfer, cleavage-stage embryo, blastocyst-stage embryo
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Sağlık Bilimleri Üniversitesi Adresli: Evet

Özet

Aim: This study aimed to compare the clinical pregnancy outcomes of Day 3 (cleavage-stage) and Day 5 (blastocyst) frozen–thawed embryo transfers in assisted reproductive technology (ART) cycles. Methods: A retrospective analysis was conducted on 6455 patients who underwent frozen–thawed embryo transfer (FET) between 1 April 2010 and 1 April 2023, at SBÜ Etlik Zübeyde Hanım Women’s Health Training and Research Hospital. Patients were categorized based on embryo transfer type, and clinical outcomes were compared using statistical analyses. Results: Pregnancy rates were significantly higher in the blastocyst transfer group (p = 0.031). The cleavage-stage group had a higher number of embryo transfers (p < 0.001), likely due to lower implantation potential per embryo. Patients with diminished ovarian reserve had lower embryo freezing rates (p < 0.001). Blastocyst-stage transfers showed better synchronization with endometrial receptivity but carried a risk of embryo attrition. Conclusions: Blastocyst transfer is associated with higher pregnancy rates and should be preferred when viable embryos are available. However, cleavage-stage transfer remains an alternative for patients with poor embryo development. An individualized approach is essential for optimizing ART outcomes.