A randomized, controlled, pilot study, for Patients ≥ 35 years and < 40 years old with sufficient ovarian reserve parameters (AFC≥ 5), but showed an unexpected poor or suboptimal ovarian response(defined as ≤ 9 retrieved oocytes in previous full-stimulation cycle, but not get live birth after all embryos were used ). In order to get better oocyte number and quality in the new COS cycle, we will compare LH supplementation from beginning with from middle of stimulation in GnRH-a long protocol.

Inclusion Criteria:

1.Infertile women, 35≤ Age< 40 years 2.18<BMI<28 Kg/m2 3.5 ≤AFC ≤20 4.Basal serum FSH≤10 IU/L, E2<70 pg/ml 5.Previous cycle as the first COS cycle,AFC ≥ 5,starting dose of FSH between 150 IU and 300IU with the possibility of adding r-hLH or hMG later in the cycle, number of oocytes retrieved ≤9 (4-9 oocytes retrieval as suboptimal responder and <4 oocytes retrieval as unexpected poor responder), but not get live birth after all embryos were used.

6.Normal uterus and at least one side of the normal ovary 7.GnRH-a long protocol, using Gonal-F® 300IU and Luveris® 150IU for COS 8.Informed consent form signed 9.Willing to follow the study protocol, and able to complete this study

Exclusion Criteria:

1. Moderate and Severe endometriosis
2. PCOS
3. Previous ovarian surgery history
4. History of recurrent miscarriages (>2 times of miscarriages)
5. Any major systemic disease that as per Investigator's discretion precludes subject for participation in the study
6. With pregnancy contraindications Alcoholism, drug abuse, drug addiction or patients with uncured sexually transmitted disease
7. According to the judgment of the Investigator, any medical condition or any concomitant surgery/medications that would interfere with evaluation of study medications
8. Simultaneous participation in another clinical study
9. Plan to use other Gn other than Gonal-F® or Luveris® during COS treatment Thyroid gland disorders