P-630 Comparison of follitropin delta versus follitropin alfa in progestin-primed ovarian stimulation in IVF
Authors: Okamoto E , Enatsu N , Yamada K , Yamada A , Hayashi N , Enatsu Y , Katayama K , Tokura Y , Yamada S , Mizusawa Y , Kishi K , Kokeguchi S , Shiotani M 
Published: June 2023

Abstract

Study question
Is there a difference in a clinical outcome between using follitropin delta and follitropin alfa undergoing a progestin primed ovarian stimulation (PPOS) protocol?

Summary answer
There was no difference between follitropin delta and follitropin alfa in terms of pregnancy rates.

What is known already
Follitropin delta (REKOVELLE, Ferring Pharmaceuticals, Switzerland) is the first recombinant human follicle-stimulating hormone (FSH) using the algorithm-based individualized dosing regimen while reducing the risk of ovarian hyperstimulation syndrome (OHSS) as compared with conventional dosing strategies. The efficacy and safety of follitropin delta has been demonstrated in randomized controlled trials (RCTs).

Study design, size, duration
We performed a retrospective analysis of 645 patients who underwent ovarian stimulation by a PPOS protocol using follitropin delta or follitropin alfa between April 2022 and August 2022. (325 patients using follitropin delta and 320 patients using follitropin alfa, respectively.)

Participants/materials, setting, methods
325 cycles of women who used follitropin delta were compared to 320 cycles of women who used follitropin alfa. The following outcomes were analysed; fertilized rate, 2 pronuclear embryo rate, good quality embryo rate, blastocyst rate, good quality blastocyst rate. A total of 499 women who underwent embryo transfer in cryo cycles using natural cycle or hormone replacement cycle were analysed about biochemical pregnancy rate, clinical pregnancy rate.

Main results and the role of chance
Baseline demographics for 325 women in follitropin delta group and 320 women in follitropin alfa were: age, 35.1±4.3 years and 35.2±4.3 years; number of previous IVF cycles, 1.6±1.6 and 1.7±1.7, respectively. The laboratory data were: fertilization rate, 81.4% and 80.1%, 2 pronuclear embryo rate, 73.9% and 71.5%, good quality cleavage stage embryo rate, 59.4% and 55.9%, blastocyst rate, 58.9% and 55.7%, good quality blastocyst rate, 41.3% and 38.7%, respectively. Only good quality cleavage stage embryo rate and good quality blastocyst rate were significantly higher (P &lt; 0.05) in follitropin delta group. A vitrified-warmed embryo transfer was performed for 257/325 women (79.1%) and 242/320 women (75.6%) and subsequent positive β-human chorionic gonadotropin (βhCG) reported for 218/621 cycles (35.1%) and 194/570 cycles (34.0%), respectively. Ongoing pregnancy rate after embryo transfer were 19.2% (n = 119) and 19.6% (n = 112) and cumulative ongoing pregnancy rate were both 46.3%. Mild OHSS was reported for 131 women (40.3%) and 170 women (53.1%), respectively (P = 0.07).

Limitations, reasons for caution
This is a non-controlled, retrospective study.

Wider implications of the findings
The present study shows that in addition to reducing the OHSS risk, follitropin delta in its individualised fixed-dose regimen has the potential to improve the quality of embryos although there was no significant difference in clinical outcomes.

Trial registration number
not applicable