Background: Controlled ovarian stimulation during in-vitro fertilization (IVF) is personalized based on anticipated hyper, normal, poor response. With respect to poor responders, who are often treated using higher gonadotropin dosing and combination of urinary and recombinant gonadotropins (rFSH) with marginal benefit, we report our experience with a newer, more potent rFSH (Follitropin-δ) undergoing IVF.
Methods: Retrospective analysis of all IVF cycles in which follitropin-δ was used alone or combined with urinary gonadotropins over a 3-year period. Patients were grouped according to the POSEIDON Classification as expected low responders (POSEIDON 3-4; AMH<1.2; N.=45), unexpected low responders (POSEIDON 1-2; retrieval of ≤9 oocytes; N.=67) and those with a normal response (N.=93). Demographic, stimulation (including target number of retrieved oocytes [8 to14]), embryology and clinical outcome parameters (clinical pregnancy rate [CPR], live birth rate [LBR], cumulative live birth rate [cLBR]) were compared.
Results: Those categorized as POSEIDON patients were older, had lower ovarian reserve, were more likely to use a mixed protocol, less likely to reach the target oocytes retrieved (35.7% vs. 51.6%, P<0.001), and had a lower cLBR per patient (29.5% vs. 38.7%, P=0.006) when compared to non-POSEIDON patients. Expected low responders (POSEIDON 3-4) were older and had lower AMH when compared to unexpected low responders (POSEIDON 1-2), but no differences in the target of oocytes retrieved (33.3% vs. 37.3%, P=0.66) and cLBR (28.9% vs. 37.3%, P=0.06) were noted.
Conclusions: In expected low responders, follitropin-δ can be used to optimize oocyte collection and clinical outcome though one may need to deviate from the algorithm-suggested dose. Future studies should explore stimulation modifications in unexpected low responders.