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Cited by 30Reproductive Biology and FertilityAssisted Reproductive Technology and Twin PregnancyReproductive Health and Technologies

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Endometrial preparation methods prior to frozen embryo transfer: A retrospective cohort study comparing true natural cycle, modified natural cycle and artificial cycle

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Mensing, Lena, Dahlberg, Emilie S., Bay, Bjørn, Gabrielsen, Anette, Knudsen, Ulla B.·2022·Archives of Gynecology and Obstetrics
DOI 10.1007/s00404-021-06371-6PMC PMC9470615
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Abstract

Purpose: The aim of this study was to compare the outcomes of three endometrial preparation methods prior to frozen embryo transfer (FET): Natural cycle (NC), modified natural cycle (mNC), and programmed/artificial cycle (AC) protocols. Primary outcomes investigated were clinical pregnancy rate (CPR) and live birth rate (LBR). Methods: A retrospective study on 2080 FET cycles including patients ≤ 35 years with a BMI ≤ 30 who underwent FET with a single autologous blastocyst stage embryo at Aarhus University Hospital or Horsens Regional Hospital in the period 2013–2019. Only blastocysts frozen by vitrification were included. No luteal phase support (LPS) was used in natural cycles. Results: In NC, mNC and AC, CPRs were 34.9%, 40.6% and 32.0%, while LBRs were 32.3%, 36.3% and 26.6%, respectively. There were no significant differences in main outcomes when comparing AC with NC [LBR: OR = 0.9 (0.6; 1.2), p = 0.4]. Compared to NC, mNC-FET displayed significantly higher positive hCG, implantation rate, CPR and LBR [LBR: OR = 1.4 (1.0; 1.9), p = 0.03]. An analysis with mNC as reference group demonstrated significantly better outcomes in the mNC group compared to AC [LBR: OR 0.6 (0.5; 0.8), p = < 0.01]. Conclusion: The present study overall demonstrated better outcomes including LBR with mNC protocol as compared to NC and AC protocol, while comparison of AC and NC showed both protocols to be equally effective. A programmed cycle may be necessary for women with anovulatory cycles; however, normo-ovulating women may be offered a natural cycle protocol. Trial registration number: 3-3013-3047/1 and 31-1522-44. Date of registration: June 24, 2019 and April 23, 2020.

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Research works printed but not linked: 35

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Metadata

Authors
Mensing, L., Dahlberg, E. S., Bay, B., Gabrielsen, A., & Knudsen, U. B.
Affiliations
  • Regional Hospital Horsens (DK)
  • Aarhus University (DK)
Corresponding author
Mensing, Lena
ORCID
Venue
Archives of Gynecology and Obstetrics
Publisher
Springer Science and Business Media LLC
Published
2022-01-30
Volume
306
Issue
4
Pages
1381-1388
ISSN
  • 0003-9128 (ISSN-L)
  • 1432-0711
DOI
10.1007/s00404-021-06371-6
PMC
PMC9470615
OpenAlex
W4210679903
Cited by
30
References
0
Citations by year
2026: 5 · 2025: 6 · 2024: 6 · 2023: 9 · 2022: 4
FWCI
5.52
Type
journal article
Language
en
Open access
Licence
Locations
  • Archives of Gynecology and Obstetrics (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Reproductive Medicine › Reproductive Biology and Fertility
  • Health Sciences › Medicine › Pediatrics, Perinatology and Child Health › Assisted Reproductive Technology and Twin Pregnancy
  • Health Sciences › Medicine › Reproductive Medicine › Reproductive Health and Technologies
Keywords
endometrial preparation, frozen embryo transfer, natural cycle, modified natural cycle, artificial cycle, clinical pregnancy rate, live birth rate, implantation rate, blastocyst vitrification, luteal phase support, anovulatory cycles
MeSH terms
Embryo Transfer, Female, Humans, Pregnancy, Retrospective Studies, Cryopreservation, Pregnancy Rate, Live Birth, Vitrification

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