In vitro fertilization has not shown a significant increase in success rates, especially in low and hypo-responders. One of the causes is oxidative stress. This study aims to determine the relationship between level of ROS, TAC and ROS-TAC score in follicular fluid with oocyte maturity rate, oocyte quality rate, fertilization rate and embryo quality rate in low and hypo-responder patients. Methods: An analytical observational study with a prospective cohort design conducted at Halim Fertility Center (HFC), Stella Maris Hospital, IVF Clinic, Division of Fertility Endocrinology Reproduction, Department of Obstetrics and Gynecology, USU Medical Faculty, Medan, from April 2021 until the number of samples is met. Results: This study was followed by 84 patients. 33 patients from Poseidon 1 (P1) group, 30 patients from P2, 12 patients from P3 and 9 patients from P4. There was no significant difference based on the demographic characteristics of each group, except for age (p<0.001), duration of infertility and duration of stimulation (p<0.001 and p=0.004). The highest ROS level was in the P1 group with a mean of 462.92. There was a significant difference in the mean ROS levels between the four groups (p=0.049). There was no significant difference in TAC and ROS-TAC levels in the four groups (p=0.524) and (p=0.460). A significant correlation was found (r=0.458) between the TAC level and the rate of embryo quality in the P1 group (p=0.007). There was no significant difference in each poseidon group between ROS, TAC and ROS-TAC scores with oocyte maturity rate, oocyte quality rate, fertilization rate and embryo quality rate in hypo-responders. Conclusion: ROS was significantly highest in the P1 group while TAC was significantly correlated with the rate of embryo quality also in the P1 group. Further research is needed to see the relationship between ROS, TAC and ROS-TAC score with oocyte quality, embryo and IVF success.

Keywords : In vitro fertilization, Hypo-responder, Lowresponder, Oocyte, Oxidative stress, ROS, TAC, ROS-TAC score, POSEIDON.