简介：AbstractGamete production is essential for mammalian reproduction. In the ovaries, the primordial follicle, which is the basic reproductive unit, is formed either perinatally or during the second pregnancy stage in humans. However, some oocytes die before the establishment of the primordial follicle pool. Consequently, it is essential to uncover how the size of the primordial follicle pool is determined and how the programmed cell death of oocytes is performed under potential surveillance. According to recent studies, the fate of oocytes in the fetal ovary seems to be determined by different protective strategies through the timely control of apoptosis or autophagy. In this review, we discuss at least three oocyte-derived protective biomarkers, glycogen synthase kinase 3 beta, X-linked inhibitor of apoptosis, and Lysine-specific demethylase 1 (also known as KDM1A), responsible for surveilling the developmental quality of fetal oocytes to coordinate primordial follicle formation in the fetal ovary. This review contributes to a better understanding of the secrets of the female reproductive reserve under physiological conditions.