Intracytoplasmic Sperm Injection in Non-male Factor Infertility in Advanced Maternal Age

Inclusion Criteria: * Female patients ages ≥38 years old with FSH ≤15; * Spouse with normal sperm analysis according to WHO fifth edition criteria(sperm parameter values: total sperm count of at least 39 million, concentration≥15 × 106/ml, total motility ≥40%, progressive motility ≥32%， strict morphology ≥4% normal forms)； * Female patients who intended to undergo IVF and had signed a written consent form. Exclusion Criteria: * More than three previous IVF cycles (including both failed cycles and cycles that ended in live births) * Female patients with Ovulation dysfunction related disease, such as endometriosis, polycystic ovarian syndrome(tubal factors are not included); undiagnosed infertility; Female patients who have previously been diagnosed with a uterine abnormality such as a malformed uterus(uterus unicornis, septate uterus, duplex uterus or uterus bicomis), adenomyosis, submucous myoma or intrauterine adhesion; * Spouse who have experienced recurrent spontaneous abortions (including biochemical pregnancy abortion), defined as three or more previous pregnancy losses; * Patients or their partners with an abnormal chromosome karyotype not including chromosome polymorphisms, which mainly refer to the variants in the chromosomal heterochromatin region * the use of donor oocytes or sperm; * the use of frozen oocytes or sperm; * Femal patients with medical conditions that contraindicate assisted reproductive technology and/or pregnancy, such as poorly controlled type 1 or type 2 diabetes mellitus; undiagnosed liver disease or dysfunction(based on serum liver enzyme test results); renal disease or abnormal serum renal function; significant anemia; history of deep venous thrombosis, pulmonary embolus or cerebrovascular accident; uncontrolled hypertension or known symptomatic heart disease; history of (or suspected) cervical carcinoma, endometrial carcinoma or breast carcinoma; and undiagnosed vaginal bleeding; * Spouse with medical conditions that contraindicate assisted reproductive technology and/or pregnancy, such as poorly controlled type 1 or type 2 diabetes mellitus; undiagnosed liver disease or dysfunction(based on serum liver enzyme test results); renal disease or abnormal serum renal function; significant anemia; history of deep venous thrombosis, pulmonary embolus or cerebrovascular accident; uncontrolled hypertension or known symptomatic heart disease; * Female patients or their partners who are unable to comply with the study Procedures; * Female patients who had previously been randomized to either of the two study groups in this trial.