Progesterone-modified Natural Cycle for FET

Summary

Hormone replacement therapy (HRT) cycles, despite the ease of synchronizing embryo thawing and embryo transfer timing, increase the risk of pregnancies and obstetric complications compared to natural cycles (NC). By ensuring the presence of the corpus luteum while reducing the number of monitoring sessions, the progesterone modified natural cycle (P4mNC) offers more convenience for the patient than the normal NC. This study is designed to compare the effects of P4mNC and HRT cycles on FET outcomes.

Timeline

Start

2025-03-05

Primary completion

2027-09-10

Completion

2028-12-01

Publications

• Background Inhorn MC, Patrizio P. Infertility around the globe: new thinking on gender, reproductive technologies and global movements in the 21st century. Hum Reprod Update. 2015 Jul-Aug;21(4):411-26. doi: 10.1093/humupd/dmv016. Epub 2015 Mar 22.
• Background Mascarenhas MN, Cheung H, Mathers CD, Stevens GA. Measuring infertility in populations: constructing a standard definition for use with demographic and reproductive health surveys. Popul Health Metr. 2012 Aug 31;10(1):17. doi: 10.1186/1478-7954-10-17.
• Background Doody KJ. Cryopreservation and delayed embryo transfer-assisted reproductive technology registry and reporting implications. Fertil Steril. 2014 Jul;102(1):27-31. doi: 10.1016/j.fertnstert.2014.04.048. Epub 2014 Jun 4.
• Background Zhang Y, Fu X, Gao S, Gao S, Gao S, Ma J, Chen ZJ. Preparation of the endometrium for frozen embryo transfer: an update on clinical practices. Reprod Biol Endocrinol. 2023 Jun 8;21(1):52. doi: 10.1186/s12958-023-01106-5.
• Background Roelens C, Blockeel C. Impact of different endometrial preparation protocols before frozen embryo transfer on pregnancy outcomes: a review. Fertil Steril. 2022 Nov;118(5):820-827. doi: 10.1016/j.fertnstert.2022.09.003.
• Background Gu F, Wu Y, Tan M, Hu R, Chen Y, Li X, Lin B, Duan Y, Zhou C, Li P, Ma W, Xu Y. Programmed frozen embryo transfer cycle increased risk of hypertensive disorders of pregnancy: a multicenter cohort study in ovulatory women. Am J Obstet Gynecol MFM. 2023 Jan;5(1):100752. doi: 10.1016/j.ajogmf.2022.100752. Epub 2022 Sep 15.
• Background von Versen-Hoynck F, Schaub AM, Chi YY, Chiu KH, Liu J, Lingis M, Stan Williams R, Rhoton-Vlasak A, Nichols WW, Fleischmann RR, Zhang W, Winn VD, Segal MS, Conrad KP, Baker VL. Increased Preeclampsia Risk and Reduced Aortic Compliance With In Vitro Fertilization Cycles in the Absence of a Corpus Luteum. Hypertension. 2019 Mar;73(3):640-649. doi: 10.1161/HYPERTENSIONAHA.118.12043.
• Background Kornilov N, Polyakov A, Mungalova A, Yakovleva L, Yakovlev P. Progesterone-modified natural cycle preparation for frozen embryo transfer. Reprod Biomed Online. 2024 Nov;49(5):104350. doi: 10.1016/j.rbmo.2024.104350. Epub 2024 Jul 2.
• Yuan HN, Song JY, Sun ZG. Comparison of progesterone-modified natural cycle and hormone replacement therapy cycle for endometrial preparation in single frozen blastocyst transfer (COMPROSET): protocol for an open-label randomized controlled trial. Front Med (Lausanne). 2025 Apr 28;12:1522004. doi: 10.3389/fmed.2025.1522004. eCollection 2025.

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Indications