How many eggs are needed for in vitro fertilization?

ovulos para fiv

In Vitro Fertilization (IVF) is an assisted reproduction treatment in which the union of the egg and the sperm takes place in a laboratory. The result of this union is the embryo, which is then placed into the maternal uterus to create a pregnancy, and in due course, the birth of a child. The success rate of in vitro fertilization is between 70 – 80%, making it an effective technique.

In this post we will explain how many eggs are needed for IVF and all about the steps necessary to decide and determine this quantity.


The number of eggs needed for IVF depends on various factors, as we will see below. Each ovarian follicle has the capacity to generate one oocyte (egg), although there are cases when the egg doesn’t fully mature, or the egg is of poor quality. Therefore, the questions arise: how many follicles are needed for this type of process to be a success? And, how many oocytes are extracted in IVF?

Below certain thresholds, it is more difficult to achieve the birth of a baby. Bearing this in mind, between 6 and 8 follicles are considered to be an adequate quantity for the treatment to go well. However, if we can increase the number of follicles, the greater chances of achieving a higher number of eggs.

Nevertheless, we always have to have a minimum number of eggs to perform IVF (even if all of the eggs are of high quality) to increase the chances of success of the treatment. Not all of them will go on to be fertilized correctly. A balanced combination of quality and quantity ensures an elevated number of viable embryos which can be frozen (vitrified) and used in case of a failed transfer, or at a later date if the patient has a desire for more children.


The first stage of the treatment is controlled ovarian stimulation, in which hormones are administered via subcutaneous injection to activate follicular development and the maturation of multiple egg cells. Once these eggs have matured, we can move to the follicular puncture step, known as egg retrieval or ovum pickup. In this step, the eggs are extracted from the ovaries and then taken to the IVF laboratory to be fertilized by the sperm.

Depending on factors such as the ovarian reserve and the woman’s age, ovarian stimulation can result in many eggs being retrieved, or only a few. Furthermore, there are follicles that may not contain an egg cell, or that the egg has not matured sufficiently in order to be fertilized. Therefore, the number of eggs obtained is very variable and depends on each individual case.

Using transvaginal ultrasound examinations before the extraction of the eggs for IVF, we can monitor the number and size of developing follicles, so that the patient has an idea of the number of eggs cells that they can generate. The final quantity of eggs is usually less than that of follicles seen in ultrasound examinations.

At Ovoclinic, we have the best team of professionals at your disposition, so you are in the best hands. If you are interested in IVF treatment, or any of our assisted reproduction services, then don´t hesitate to get in touch with us. We would be delighted to help you.

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