Optimizing luteal support in frozen embryo transfer cycles - Fertility and Sterility

There is a paucity of high-quality literature on luteal support in frozen embryo transfer cycles, and there is no consensus regarding the optimal formulation, route, dosage, or duration of progesterone. A Cochrane review in 2010 (1x1Glujovsky, D., Pesce, R., Fiszbajn, G., Sueldo, C., Hart, R.J., and Ciapponi, A. Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes. Cochrane Database Syst Rev. 2010; : CD006359 PubMed | Google ScholarSee all References)(1) concluded that “there is insufficient evidence to recommend any one particular protocol.” A more recent meta-analysis (2x2Mackens, S., Santos-Ribeiro, S., van de Vijver, A., Racca, A., Van Landuyt, L., Tournaye, H. et al. Frozen embryo transfer: a review on the optimal endometrial preparation and timing. Hum Reprod. 2017; 32: 2234–2242 Crossref | PubMed | Scopus (5) | Google ScholarSee all References)(2) drew similar conclusions. Optimizing frozen embryo transfer cycles is of utmost importance, as the number of assisted reproductive technology (ART) cycles performed for banking embryos and oocytes has increased more than 10-fold over the past 10 years (3x3Centers for Disease Control and Prevention. 2015 assisted reproductive technology national summary report figures. (Available at:)https://www.cdc.gov/art/reports/2015/national-summary-figures.html. Google ScholarSee all References)(3). In this issue of Fertility and Sterility, Devine et al. (4x4Devine, K., Richter, K.S., Widra, E.A., and McKeeby, J.L. Vitrified blastocyst transfer cycles using only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-armed randomized non-inferiority trial. Fertil Steril. 2018; 109: 266–275 Abstract | Full Text | Full Text PDF | PubMed | Scopus (5) | Google ScholarSee all References)(4) report on the interim analysis of a well-designed, blinded, randomized control trial that provides a timely update on hormone support for programmed cryo-thaw blastocyst cycles. This study consisted of three arms: 50 mg daily intramuscular (IM) progesterone; 200 mg twice daily vaginal Endometrin (Ferring Pharmaceuticals); and 200 mg twice daily vaginal Endometrin plus 50 mg IM progesterone every third day. The three groups were designated A, B, and C, with group C revealed to be the Endometrin vaginal-progesterone-only group at completion of the interim analysis. Groups A and B remain blinded until completion of the study. The clinical pregnancy rate was higher in the groups who