TY - JOUR
T1 - Immediate versus postponed single blastocyst transfer in modified natural cycle frozen embryo transfer (mNC-FET)
T2 - a study protocol for a multicentre randomised controlled trial
AU - Bergenheim, Sara Johanna
AU - Saupstad, Marte
AU - Pistoljevic, Nina
AU - Lyng Forman, Julie
AU - Larsen, Elisabeth Clare
AU - Bogstad, Jeanette Wulff
AU - Fynbo, Malene
AU - Hashem, Nadia
AU - Freiesleben, Nina La Cour
AU - Nøhr, Bugge
AU - Andersen, Lars Franch
AU - Humaidan, Peter
AU - Ziebe, Soren
AU - Pinborg, Anja Bisgaard
AU - Løssl, Kristine
N1 - © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
PY - 2021/10/27
Y1 - 2021/10/27
N2 - INTRODUCTION: Today, it is widespread practice to postpone frozen embryo transfer (FET) in a modified natural cycle (mNC) for at least one menstrual cycle after oocyte retrieval and failed fresh embryo transfer or freeze-all. The rationale behind this practice is the concern that suboptimal ovarian, endometrial or endocrinological conditions following ovarian stimulation may have a negative impact on endometrial receptivity and implantation. However, two recent systematic reviews and meta-analyses based on retrospective data did not support this practice. As unnecessary delay in time to transfer and pregnancy should be avoided, the aim of this study is to investigate if immediate single blastocyst transfer in mNC-FET is non-inferior to standard postponed single blastocyst transfer in mNC-FET in terms of live birth rate.METHODS AND ANALYSIS: Multicentre randomised controlled non-blinded trial including 464 normo-ovulatory women aged 18-40 years undergoing single blastocyst mNC-FET after a failed fresh or freeze-all cycle. Participants are randomised 1:1 to either FET in the first menstrual cycle following the stimulated cycle (immediate FET) or FET in the second or subsequent cycle following the stimulated cycle (postponed FET). The study is designed as a non-inferiority trial and primary analyses will be performed as intention to treat and per protocol.ETHICS AND DISSEMINATION: Ethical approval has been granted by the Scientific Ethical Committee of the Capital Region of Denmark (J-nr.: H-19086300). Data will be handled according to Danish law on personal data protection in accordance with the general data protection regulation. Participants will complete written consent forms regarding participation in the study and storage of blood samples in a biobank for future research. The study will be monitored by a Good Clinical Practice (GCP)-trained study nurse not otherwise involved in the study. The results of this study will be disseminated by publication in international peer-reviewed scientific journals.TRIAL REGISTRATION NUMBER: NCT04748874; Pre-results.
AB - INTRODUCTION: Today, it is widespread practice to postpone frozen embryo transfer (FET) in a modified natural cycle (mNC) for at least one menstrual cycle after oocyte retrieval and failed fresh embryo transfer or freeze-all. The rationale behind this practice is the concern that suboptimal ovarian, endometrial or endocrinological conditions following ovarian stimulation may have a negative impact on endometrial receptivity and implantation. However, two recent systematic reviews and meta-analyses based on retrospective data did not support this practice. As unnecessary delay in time to transfer and pregnancy should be avoided, the aim of this study is to investigate if immediate single blastocyst transfer in mNC-FET is non-inferior to standard postponed single blastocyst transfer in mNC-FET in terms of live birth rate.METHODS AND ANALYSIS: Multicentre randomised controlled non-blinded trial including 464 normo-ovulatory women aged 18-40 years undergoing single blastocyst mNC-FET after a failed fresh or freeze-all cycle. Participants are randomised 1:1 to either FET in the first menstrual cycle following the stimulated cycle (immediate FET) or FET in the second or subsequent cycle following the stimulated cycle (postponed FET). The study is designed as a non-inferiority trial and primary analyses will be performed as intention to treat and per protocol.ETHICS AND DISSEMINATION: Ethical approval has been granted by the Scientific Ethical Committee of the Capital Region of Denmark (J-nr.: H-19086300). Data will be handled according to Danish law on personal data protection in accordance with the general data protection regulation. Participants will complete written consent forms regarding participation in the study and storage of blood samples in a biobank for future research. The study will be monitored by a Good Clinical Practice (GCP)-trained study nurse not otherwise involved in the study. The results of this study will be disseminated by publication in international peer-reviewed scientific journals.TRIAL REGISTRATION NUMBER: NCT04748874; Pre-results.
KW - clinical trials
KW - reproductive medicine
KW - subfertility
UR - http://www.scopus.com/inward/record.url?scp=85118859940&partnerID=8YFLogxK
U2 - 10.1136/bmjopen-2021-053234
DO - 10.1136/bmjopen-2021-053234
M3 - Journal article
C2 - 34706963
SN - 2044-6055
VL - 11
SP - 1
EP - 7
JO - BMJ Open
JF - BMJ Open
IS - 10
M1 - e053234
ER -