What are the reasons for the failure of fresh embryos in IVF?

Patient's question:

Infertility

Doctor's answer:

Reasons for IVF failure:
1. No response or poor response to stimulation drugs for ovulation, resulting in the ovaries not producing a sufficient number of mature eggs.
2. Difficulty in egg retrieval or failure to retrieve eggs due to special anatomical reasons in the patient's pelvic cavity.
3. 20% of eggs fail to fertilize due to inherent issues with the eggs or insufficient/weak sperm.
4. 20% of fertilized eggs fail to develop normally or undergo degenerative changes, preventing them from being implanted into the uterine cavity.