The demographic and baseline characteristics between two study groups (< 38 and ≥ 38 years) were comparable, including duration and cause of infertility, primary infertility or secondary infertility, baseline concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and thyroid stimulating hormone (TSH) before treatment. This evidence concerns the gene PLOD1 and Infertility.