What does the number of eggs obtained by IVF have to do with? Why do some people obtain more than 20 eggs and others only 1-2, or even none? Let’s look at the reasons. 1. What is the principle of obtaining eggs by IVF? First of all, we need to look at the principle of ovulation. Every month, a group of follicles enter the “follicular pool” in a woman’s ovaries, and these follicles are activated and begin to develop. Under normal circumstances, the follicle development hormones and feedback provided by the body can only give a total of one dominant follicle in the pool to develop, and only one or occasionally two follicles can be obtained from the pool during a menstrual cycle, but after the activation of the follicle pool the other follicles atrophy and disappear due to lack of sufficient “nutrients”. The process of IVF ovulation promotion involves exogenously administering the hormones needed to promote follicle growth, and ovulating the follicles that enter the “follicular pool” to obtain as many eggs as possible. By using this principle, we can solve two common problems: (1) ovulation promotion makes use of the follicles in the follicular pool that might otherwise be atretic, and makes full use of these follicles, so there is no concern that ovulation promotion will cause fewer and fewer follicles; (2) the number of eggs in the follicular pool is the basis for the number of eggs obtained in the final egg retrieval. (2) The number of eggs in the follicular pool is the basis for the number of eggs obtained in the final egg retrieval. 2. What are the possible factors for the low number of eggs obtained in IVF? By understanding the principles of ovulation promotion, it becomes easier to understand the possible reasons for the low number of eggs obtained during IVF. (1) Advanced age: As the number of eggs in the follicular pool decreases with age, fewer eggs will be retrieved by ovulation. (2) Premature ovarian failure: In a small number of young people, the ovaries age prematurely and the number of eggs in the follicular pool becomes lower early, and fewer eggs will be obtained by ovulation. (3) Low ovarian response: follicles in the follicular pool respond poorly to exogenously administered follicle stimulating hormone and have difficulty growing to maturity, which also results in fewer eggs being obtained. (4)
Empty follicles: The number of follicles in the follicular pool is not a problem, but the eggs in the follicles are missing, just like an egg with only egg white but no yolk, and the embryologist cannot find the eggs after egg retrieval, which is also one of the reasons for the low number of eggs obtained. It should be noted that in actual clinical practice, the probability of empty follicle syndrome is very low. Other factors: If the egg retrieval technique is immature, it may lead to loss of eggs, but this is very unlikely to happen because each egg retrieval surgeon has undergone rigorous training for more than a decade and the retrieval technique has been observed and supervised by a superior surgeon for a long time before he/she can perform the egg retrieval procedure alone.