There were no significant differences seen in female age, male age, BMI, duration of sterility, FSH, LH, E2, PRL, T, FSH/LH, number of baseline antral follicles in left or right ovary, mean Gn concentration, mean duration of Gn per cycle, or mean endometrial thickness between the pregnant and non-pregnant groups (all P values > 0.05). This evidence concerns the gene PLOD1 and infertility disorder.