A 5-year multicentre randomized controlled trial comparing personalized, frozen and fresh blastocyst transfer in IVF

Reprod Biomed Online. 2020 Sep;41(3):402-415. doi: 10.1016/j.rbmo.2020.06.002. Epub 2020 Jun 15.


Research question: Does clinical performance of personalized embryo transfer (PET) guided by endometrial receptivity analysis (ERA) differ from frozen embryo transfer (FET) or fresh embryo transfer in infertile patients undergoing IVF?

Design: Multicentre, open-label randomized controlled trial; 458 patients aged 37 years or younger undergoing IVF with blastocyst transfer at first appointment were randomized to PET guided by ERA, FET or fresh embryo transfer in 16 reproductive clinics.

Results: Clinical outcomes by intention-to-treat analysis were comparable, but cumulative pregnancy rate was significantly higher in the PET (93.6%) compared with FET (79.7%) (P = 0.0005) and fresh embryo transfer groups (80.7%) (P = 0.0013). Analysis per protocol demonstrates that live birth rates at first embryo transfer were 56.2% in PET versus 42.4% in FET (P = 0.09), and 45.7% in fresh embryo transfer groups (P = 0.17). Cumulative live birth rates after 12 months were 71.2% in PET versus 55.4% in FET (P = 0.04), and 48.9% in fresh embryo transfer (P = 0.003). Pregnancy rates at the first embryo transfer in PET, FET and fresh embryo transfer arms were 72.5% versus 54.3% (P = 0.01) and 58.5% (P = 0.05), respectively. Implantation rates at first embryo transfer were 57.3% versus 43.2% (P = 0.03), and 38.6% (P = 0.004), respectively. Obstetrical outcomes, type of delivery and neonatal outcomes were similar in all groups.

Conclusions: Despite 50% of patients dropping out compared with 30% initially planned, per protocol analysis demonstrates statistically significant improvement in pregnancy, implantation and cumulative live birth rates in PET compared with FET and fresh embryo transfer arms, indicating the potential utility of PET guided by the ERA test at the first appointment.

Keywords: Endometrial receptivity; Endometrial receptivity analysis (ERA); Fresh embryo transfer (ET); Frozen embryo transfer (FET); Personalized embryo transfer (PET); Window of implantation (WOI).

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Birth Rate
  • Cryopreservation
  • Embryo Transfer / methods*
  • Female
  • Fertilization in Vitro / methods*
  • Humans
  • Infertility, Female / therapy*
  • Live Birth
  • Pregnancy
  • Pregnancy Rate
  • Treatment Outcome