The purpose of this randomized clinical trial is to compare the efficacy and safety with transfer of embryos selected by next generation sequencing (NGS) versus conventional morphological criteria. Subjects with 3 or more blastocysts on day 5 of embryo culture will be randomized to the PGS or IVF group. A Freeze-all strategy and a single frozen blastocyst transfer will be performed in both PGS and IVF groups. The primary outcome is the cumulative live birth after transfers of up to 3 single blastocycsts in both groups.

This is a multicenter, randomized clinical trial comparing the efficacy and safety with transfer of embryos selected by next generation sequence (NGS) and morphologic criteria versus by morphological criteria alone. Subjects who obtain 3 or more good-quality blastocysts will be randomized to PGS or IVF group. All embryos will be frozen and a single thawed blastocyst will be transferred in both PGS and IVF group. Subjects in the PGS group will have 3 blastocysts sequenced and euploid embryos will be subsequently transferred. Subjects in the IVF group will have blastocysts selected by morphology assessment. The cumulative live birth rate will be counted after transfers of all euploid embryo in the PGS group and 3 blastocysts in the IVF group within 1 year after randomization.

Inclusion Criteria:

1. Women who are participating in their first cycle of IVF or ICSI
2. Women ages 20 to 37 years.
3. Women who obtain 3 or more good-quality blastocysts defined as morphological score of inner cell mass B or A, trophectoderm C or better, and grade 4 or better on day 5 of embryo culture will be randomized.

Exclusion Criteria:

1. Women with a uterine cavity abnormality, such as a uterine congenital malformation (uterus uni-cornate, bicornate, or duplex); untreated uterine septum, adenomyosis, submucous myoma, or endo-metrial polyp(s); or with history of intrauterine adhesions.
2. Women with untreated hydrosalpinx;
3. Women who are indicated and planned to undergo PGD, for example, parental abnormal karyo-type or diagnosed with monogenic disease;
4. Women who use donated oocytes or sperm to achieve pregnancy;
5. Women with contraindication for assisted reproductive technology or for pregnancy, such as poorly controlled Type I or Type II diabetes; undiagnosed liver disease or dysfunction (based on se-rum liver enzyme testing); renal disease or abnormal serum renal function; significant anemia; history of deep venous thrombosis, pulmonary embolus, or cerebrovascular accident; uncontrolled hyper-tension, known symptomatic heart disease; history of or suspected cervical carcinoma, endometrial carcinoma, or breast carcinoma; undiagnosed vaginal bleeding.