With the development of society, more and more aged pregnant women because of various reasons, their abnormality rate of egg chromosome was higher than that of young women, then the abnormality rate of embryo chromosome is higher too, so the pregnancy rate in aged women is lower, abortion rate is higher. In order to improve the pregnancy rate in aged women, cut down their abortion rate 、fetal birth with abnormal chromosome, and the risk of pregnancy termination after the prenatal diagnosis, reduce their pain of body and mind, the investigators will carry out this study. This is a prospective randomized controlled study of preimplantation genetic screening with Next generation sequencing technology. The embryos with more developmental potential and normal chromosomes should be selected. There is no related studies in Chinese. Most international research are limited to fluorescence in situ hybridization (FISH) technique, not on the embryo chromosome comprehensive screening. So there is no evidence of the effects of PGS on advanced age women.

This study is to compare the outcomes between the advanced age women with two methods respectively. After blastocyst culture, blastocysts will be transferred in the control group. In the Preimplantation Genetic Screening (PGS) group, blastocyst embryo trophoblast biopsy will be performed and chromosome screening with Next generation sequencing（NGS） technology, at the same time, the blastocysts will be frozen, then the blastocysts with normal chromosome will be thawed and transferred. The investigators expect that, in PGS group live birth rate 、cancellation rate and pregnancy rate are higher than in control group; abortion rate is lower than that of the control group.

Inclusion Criteria:

• Premenopausal females, age ≥37 years ≤44 years
• Have given birth to a healthy baby
• Bilateral ovaries
• Antral follicle count(AFC)≥10,and Anti Mullerian Hormone (AMH)≥2.0 ng/ml

Exclusion Criteria:

• Endometriosis disease

• Intrauterine adhesions history; intrauterine membrane polyp, tuberculosis and inflammation,

• Uterine malformation, multiple uterine myoma, uterine intramural myoma >3cm, submucous myoma;

• Unprocessed hydrosalpinx

• Adverse reproductive history; greater than or equal to 2 times history of unexplained abortion

• Chromosomal abnormalities or other genetic disease

• Infertility caused by male factors, such as puncture testicular, SRT did not see the class A and class B sperm

• Without high quality embryos in past controlled ovarian hyperstimulation (COH)cycles.

• Patients with poor ovarian response, the standard of poor ovarian response accords with Bolognacriteria standard, that is at least meet 2 among the following 3:

  1. . Elder years (≥40 years) or have other known inherited or acquired risk factors that may reduce follicle.
  2. .History of cancellation of the cycles because of less than 3 follicular development, or history of egg number less than 4 after at least using Follicle-Stimulating Hormone(FSH) 150IU once a day.
  3. .Ovarian reserve function test abnormalities, including sinus follicle number less than 5-7 AFC or AMH less than 0.5 to 1.1 ng/ml