Patients in experimental group will be given transcutaneous electrical acupoint stimulation (TEAS) treatment for 12 weeks prior to controlled ovarian stimulation (COS).The patients will be given three times acupuncture every week except menstruation.Patients in no intervention group will not be given any interventions for 12 weeks prior to COS. The primary outcome measure is the number of MII eggs obtained in the COS cycle. The secondary outcome measures are the lab and clinical reproductive outcomes.

The patients will be randomly recruited into two groups. Patients in experimental group will be given TEAS treatment for 12 weeks prior to COS.The patients will be given three times acupuncture every week except menstruation. One treatment lasts for 30 minutes. The acupoints used for the TEAS treatment included head acupoint Baihui(DU20), abdominal acupoint Zhongji (RN3), Guanyuan (RN4), Zigong(EX-CA1), leg acupoint Sanyinjiao(SP6), waist acupoint Shenyu (BL23) and Guanyuanyu(BL26). Patients in no intervention group will not be given any intervention for 12 weeks prior to COS. When at least one dominant follicle is greater than 18 mm then injection a GnRH agonist (Triptorelin, Ferring, Switzerland) 0.2mg. 36 hours later transvaginal oocyte retrieval will be taken. After 3 hours of incubation, each egg will be transferred with a density of about 100,000/mllive sperm. The fresh embryo transfer is performed 72 hours after embryo culture in vitro. The whole embryos will be frozen.

The primary outcome measure is the number of MII eggs obtained in the COS cycle. The secondary outcome measures are the lab and clinical reproductive outcomes,including basic endocrine, serum Anti-Mullerian Hormone （AMH）, antral follicle counts, fertilization rate, cleavage rate, number of D3 embryos, the clinical pregnancy rate and early abortion rate.

Inclusion Criteria:

1. The poor ovarian response patients compliance with Bologna consensus
2. Age：20-45 year
3. Women undergoing IVF-ET because of infertility for more than one year.

Exclusion Criteria:

1. Patients with genital tract malformation. Uterine malformation (single uterus, double uterus, double uterus, untreated mediastinal uterus) and other effects affecting uterine cavity disease (adenomyosis, submucosal uterine fibroids, intrauterine adhesions and scar uterus)
2. Complicated with other medical diseases（Hypertension, diabetes, psychosis, hereditary diseases）