PCOS: polycystic ovarian syndrome; DOR: Diminished ovarian reserve; BMI: body mass index; AFC: antral follicle count; AMH: Anti-mullerian hormone; COH: controlled ovarian stimulation; PPOS: progestin primed ovarian stimulation; IVF: in vitro fertilization; ICSI: intracytoplasmic sperm injection; SMD: Standardized Mean Difference. The gene discussed is AMH; the disease is polycystic ovary syndrome.