This study is a prospective, randomized, parallel, controlled trial to assess the efficacy of the late follicular phase administration of low dose hCG on oocyte maturity for ovarian stimulation in 73 poor respond patients undergoing intracytoplasmic sperm injection (ICSI) treatment.

In this study all eligible patients were randomly allocated into three study groups by a permuted block randomization method: group A (control group) received only recombinant FSH, group B received rFSH supplemented by 100IU hCG in the late follicular phase. Group C received rFSH supplemented by 200IU hCG in the late follicular phase.

All of the patients underwent a standard long protocol and received GnRH-a (Suprefact), 0.5cc subcutaneous, started from the day 17 of the preceding cycle and ovulation induction was started 14 days thereafter.

Patients were categorized according to the following stimulation protocols:

Group A (control group): which 300 IU r-FSH was administered for the first 5 days of the stimulation cycle. Then the first ultrasound scan was performed to monitor response. At this stage the dose of rFSH adjusted according to the ovarian response and continued until the day of ovulatory hCG administration.

Group B: rFSH supplemented with daily administration of 100 IU hCG in the late follicular phase based on the follicle size (14mm).

Group C: rFSH supplemented with daily administration of 200 IU hCG in the late follicular phase based on the follicle size (14mm).

To assess the pregnancy outcomes, serum hCG was measured 2 weeks after embryo transfer. Clinical pregnancy was defined by the observation of sac with fetal heart rate on ultrasonography 4 weeks after embryo transfer.

Inclusion Criteria:

1. Poor ovarian response to ovulation induction according to the ESHRE definition[20] and presence of at least 2 of the criteria needed to define poor responders including advanced maternal age, history of low ovarian response in previous IVF/ICSI treatments and abnormal ovarian reserve test(Antral Follicle number < 5)
2. indication for ICSI treatment, second or third cycle
3. Age 37 to 43 years
4. Body mass index (BMI) ≤ 30 kg/m2
5. The presence of two functional ovaries and no previous ovarian surgery
6. The presence of normal uterine cavity and 2 normal tubes base on recent hysterosalpingographic or hysteroscopic evaluation
7. Basal (day 2 or 3) serum FSH levels ≤13 IU/L
8. Normal semen analysis
9. No history or signs of endometriosis
10. No untreated endocrinologic disease