The goal of this clinical trial is to test MVA on improving pregnancy outcome in elderly infertile patients undergoing invitro fertilization (IVF). The main question it aims to answer is whether MVA could improve embryo haploid rate. Participants requested IVF are asked to randomly culture equal numbers of oocyte and embryo with or without MVA. Therefore, sibling oocytes were randomly divided into test group and control group.

After being informed about the study and potential risks, all participants will write the informed contents. This study is a randomized controlled study co compare different treatment methods on the embryo development. Sibling eggs were randomly divided into test group and control group. Specific method of randomization: all the eggs of each subject were distributed into two dishes (dish 1 and dish 2). If the oocyte number is odd, put the extra oocyte into dish 1. Using statistical software, the two dishes were randomly treated as test group and control group. Thus, a random allocation table was generated and a separate random envelope was made for each subject. The random envelope is kept and distributed by the relevant personnel who are not involved in the screening and treatment of subjects and are authorized by the researcher. Each selected subject must open the random envelope. The subjects were subjected to routine ovulation promotion, and then the acquired oocytes and cumulus cell complexes (COCs) were obtained and fertilized in vitro. The test group oocytes were cultured with MVA, while the control oocytes were cultured without MVA. Thus, half of the eggs from each elderly infertile patient were treated with MVA.

Inclusion Criteria:

1. 38 years ≤ age ≤ 42 years;
2. Number of IVF/ICSI cycles ≤ 2

Exclusion Criteria:

1. Egg donor cycle
2. Chromosome abnormality;
3. Adenomyosis, hysteromyoma, thin endometrium, endometriosis and other uterine diseases;
4. Patients with repeated implantation failure