PErsonalized Addition of Recombinant LH in Suboptimal Responders >35 Years Old (POSEIDON Group 2): A Randomized Controlled Trial

The main objective of assisted reproductive technology is to achieve a healthy child. Many aspects play a role in order to reach this outcome, including female age, the number of oocytes retrieved after ovarian stimulation, and endometrial receptivity. It has been clearly demonstrated that the number of oocytes obtained after ovarian stimulation for IVF/ICSI is a surrogate marker for the success rates following treatment. In general, a high number of oocytes retrieved is translated into a high number of embryos and eventually a high cumulative pregnancy rate (after the transfer of fresh and frozen-thawed embryos). However, although a higher number of oocytes and embryos may ensure an increase in the cumulative pregnancy rate, excessive ovarian response has been postulated to have a detrimental effect on the pregnancy rates following fresh embryo transfer given that raised serum estradiol and progesterone levels associated with a very excessive response may negatively affect embryo implantation.

In assisted reproductive technology (ART) cycles under the GnRH analog regimens, elevated progesterone serum levels at the late follicular phase, in good ovarian reserve women, is thought to be related to multiple follicular development and increased ovarian steroidogenic activity. However, for these patients elevated progesterone was shown to negatively affect the endometrium preparation and thereby implantation rate. Furthermore, in this group of women elevated progesterone is advocated to have no negative effect on the oocyte or embryo quality.

Importantly, more pronounced effect on unbalanced steroidogenesis has been correlated with age and ovarian reserve. For this patient population, serum progesterone/estradiol (P/E2) ratio on the day of human chorionic gonadotropin (hCG) administration was suggested as a more reliable marker predictor to cycle success than solely progesterone rise.

Based on the above-mentioned reports it is relatively clear that the aim of ovarian stimulation should be to result in high oocyte yield and educate endocrine milieu in order to maximize cumulative live birth rates. Nevertheless, despite this goal, a substantial proportion of patients do not manage to reach an optimal oocyte yield, resulting in lower pregnancy rates. These hypo-responders are associated with low follicles growth and reduced estrogen production leading to longer stimulations, and/or greater cumulative FSH doses.

Although, it is widely accepted that poor ovarian responders have significantly low live birth rates as compared with all other groups, an intermediate group of women with a "suboptimal ovarian response", has been recently proposed as a distinct group with significantly worse prognosis from women with normal response. In the same line, the POSEIDON group (Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number) has recently proposed a new stratification for patients with a reduced ovarian reserve or unexpected inappropriate ovarian response to ovarian stimulation, taken into account quantitative and qualitative parameters such as: i. Age and the expected aneuploidy rate; ii. Ovarian biomarkers (mainly antral follicle count (AFC) and anti-Müllerian hormone (AMH)), and iii. Ovarian response to a previous stimulation cycle.