title: The novel POSEIDON stratification of 'Low prognosis patients in Assisted Reproductive Technology' and its proposed marker of successful outcome.
abstract: In reproductive medicine little progress has been achieved regarding the clinical management of patients with a reduced ovarian reserve or poor ovarian response (POR) to stimulation with exogenous gonadotropins -a frustrating experience for clinicians as well as patients. Despite the efforts to optimize the definition of this subgroup of patients, the existing POR criteria unfortunately comprise a heterogeneous population and, importantly, do not offer any recommendations for clinical handling. Recently, the POSEIDON group (Patient-OrientedStrategiesEncompassingIndividualizeD OocyteNumber) proposed a new stratification of assisted reproductive technology (ART) in patients with a reduced ovarian reserve or unexpected inappropriate ovarian response to exogenous gonadotropins. In brief, four subgroups have been suggested based on quantitative and qualitative parameters, namely, i. Age and the expected aneuploidy rate; ii. Ovarian biomarkers (i.e. antral follicle count [AFC] and anti-Müllerian hormone [AMH]), and iii. Ovarian response - provided a previous stimulation cycle was performed. The new classification introduces a more nuanced picture of the "low prognosis patient" in ART, using clinically relevant criteria to guide the physician to most optimally manage this group of patients. The POSEIDON group also introduced a new measure for successful ART treatment, namely, the ability to retrieve the number of oocytes needed for the specific patient to obtain at least one euploid embryo for transfer. This feature represents a pragmatic endpoint to clinicians and enables the development of prediction models aiming to reduce the time-to-pregnancy (TTP). Consequently, the POSEIDON stratification should not be applied for retrospective analyses having live birth rate (LBR) as endpoint. Such an approach would fail as the attribution of patients to each Poseidon group is related to specific requirements and could only be made prospectively. On the other hand, any prospective approach (i.e. RCT) should be performed separately in each specific group.
authors.affiliation: Fertility Clinic, Skive Regional Hospital, Skive, Denmark; Faculty of Health, Aarhus University, Skive, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Humaidan
authors.affiliation: Department of Neuroscience, Reproductive Science and Odontostomatology, University of Naples Federico II, Naples, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Alviggi
authors.affiliation: Fertility Center Hamburg, Hamburg, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Fischer
authors.affiliation: ANDROFERT, Andrology & Human Reproduction Clinic, Campinas, Brazil.
authors.forename: Sandro C
authors.identifier: 0000-0002-1313-9680
authors.initials: SC
authors.lastname: Esteves
keywords: Assisted Reproductive Technology; Diagnosis; Embryo aneuploidy; Gonadotropins; Group POSEIDON; Ovarian stimulation; Poor ovarian response; Prognosis.