Poor ovarian response (POR) remains one of the significant challenges of Assisted Reproductive Technology (ART). Patients with POR yield a low number of oocytes, leading to a low number of useable embryos and a decline in the live birth rate. According to the consensus of the European Society of Human Reproduction and Embryology (ESHRE) in 2011, POR was diagnosed using Bologna criteria. However, some recent studies show the classification by Bologna is not efficient, because the oocyte number should be combined with female age since the likelihood of achieving a live birth among patients with similar oocyte yield ultimately depends on the age of the patient. In 2016, POSEIDON (Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number) Group was established and released the new criteria. The POSEIDON criteria proposed a shift from the terminology of POR to the concept of low prognosis. According to POSEIDON criteria, low prognosis account for 30-40% of all stimulated in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. The low prognosis patient is classified into four groups according to the results of ovarian reserve markers (AMH, AFC, or both), female age, and the number of oocytes retrieved in previous cycles, such as: maternal age \< 35, AMH ≥ 1,2 ng/ml and AFC ≥ 5 (subgroup 1a: \< 4 oocytes; subgroup 1b: 4-9 oocytes); maternal age ≥ 35, AMH ≥ 1,2 ng/ml and AFC ≥ 5 (subgroup 2a: \< 4 oocytes; subgroup 2b: 4-9 oocytes); maternal age \< 35, AMH \< 1,2 ng/ml and AFC \< 5; maternal age ≥ 35, AMH \< 1,2 ng/mL and AFC \< 5. Although many efforts have been made to improve treatment outcomes in this group of patients, such as researching, understanding, and modifying clinical ovarian stimulation regimens, the results are still not feasible. Especially, group 4, which have advanced maternal age (≥ 35) and seized for 14.4% of low prognosis, has a low cumulative live birth rate (11% in group 4). Female age is a critical element in the POSEIDON classification because age is crucially related to embryo ploidy and more importantly live birth outcome. The probability of having embryo ploidy sharply declined after the age of 34 and was lower than 50% in women aged 35 years and over. Therefore, patients in group 4 will have an increased risk of aneuploidy embryos, decreasing the live birth rate in these groups of patients. A recent study evaluated cumulative live birth rates per cycle, there was a remarkable difference between POSEIDON patients (21, 43, 10, 25, 29, and 17% in groups 1a, 1b, 2a, 2b, 3, and 4, respectively) and non-POSEIDON counterparts (52%). Facing difficulties related to clinical practice, optimizing the embryo culture process is necessary to improve the embryo number and quality in the POR group. Potential techniques include follicular size at the trigger, dual trigger, artificial oocyte activation (AOA), blastocyst transfer, and the role of preimplantation genetic testing for aneuploidy (PGT-A).

In Vietnam, AOA was first reported in 2011, performing on 1588 oocytes, and said the fertilization rate was higher in the ICSI - AOA than in the ICSI group (80.8% vs 74.3%, respectively; p\<0.002).

AOA is expected to improve treatment outcomes for low prognosis patients, especially in group 4 by the POSEIDON criteria with the potential for clinical efficacy and safety. Therefore, this study aims to evaluate the effectiveness and safety of AOA on treatment outcomes in low prognosis patients defined by the POSEIDON criteria (2016).