Characteristics of 20 included trials on basic information.

Women who accepted IVF and failed once (or more) before;IVF: in vitro fertilization; HG: Herbal group; CG: Control group; ITO: infertility of tubal origin; POS: polycystic ovarian syndrome; GnRH-a: GnRH-a gonadotropin releasing hormone agonist; GnRH-a+: GnRH-a long programme+corpus luteum (with fresh embryo transfer); GnRH-a−: GnRH-a short programme+corpus luteum (with fresh embryo transfer); FET: frozen embryo transfer; FR: fertilization rate; HQER: high quality embryos rate; CPR: clinical pregnancy rate; AR: abortion rate; NTE: No. of transferred embryos; IR: implantation rate; OHSS: ovarian hyper stimulation syndrome; OPR: ongoing pregnancy rate; ET: endometrial thickness; HL: hormone levels.