Answer from: Raúl Olivares, MD
That will depend on the age of the patient. If the patient is younger than 35, it’s very likely that if we have 6 eggs, we may end up with 2 or 3 good embryos with good implantation chances. If the patient is over 40-42, probably most of these eggs are going to have genetic issues, and we may not get a lot of embryos, or the embryos that we get may have genetic issues.
That’s why the older the patient is, the more eggs we need because we’re going to have fewer embryos or embryos with a higher genetic risk.
So for a patient younger than 35, 6 eggs seem like a good number. If you are older than 40, 6 eggs do not seem to be enough.
Answer from: Anna Voskuilen, MD
Let me start by explaining that this depends on the age of the patient because it is going to be based on the quality of the eggs. Secondly, every patient responds differently to what we call the IVF funnel. An IVF funnel is this: not all the follicles we see at the beginning of a cycle respond to the medication, not all these follicles will come out in the egg retrieval, not all of these follicles will be mature, not all the mature ones will be fertilized, and not all the ones that are fertilized will arrive at the stage of blastocyst.
So if you ask if 6 eggs are enough to have a good outcome, it will always depend on the response of the patient to the stimulation. But to increase the number of follicles we do mild stimulation protocol for patients that do not respond to normal protocol stimulation, and still we go for IVF, for the egg retrieval and we do this because we know it will help.
In patients with low ovarian reserve where we have fewer eggs we would probably we would need more cycles. Sometimes we do more cycles as some patients accumulate eggs in different cycles. For sure, 6 eggs would be enough to try IVF.
Answer from: Aleksandr Darii, PhD
It’s necessary to obtain eggs, oocytes, and sperm for artificial insemination. Oocytes will be fertilised in-vitro in an embryological laboratory. With the stimulated protocol, a woman receives not one egg in one menstrual cycle but several eggs at once, an average of 10-15 cells. In this case, by the time of puncture, the cells all or part of them may be immature. It depends on various factors; if we take a small number of oocytes, the probability of receiving embryos decreases. To get a good result, we need between 4 and 8 cells. Then even if some portion of the oocytes is not fertilised, there is still a chance for success.
Not each oocyte is suitable for fertilisation. To do this, they must reach a certain stage of maturity. During ICSI (Intracytoplasmic Sperm Injection), the sperm is injected directly into the oocyte. The day after the procedure, we can see which oocytes are fertilised successfully.
In the next five days, they will transform from zygotes to blastocysts. The success depends on the initial quality of eggs and sperm. Natural selection of this stage occurs both in the laboratory and invitro. That is why even healthy couples don’t always become pregnant in the first months of open sex life.
Answer from: Alina Horbenko, MD
Sometimes, even one oocyte is enough for the successful IVF cycle. For example, in the natural cycle IVF programs, we work with one or two eggs that are obtained without ovarian stimulation. This approach is often resorted to for patients under the age of 30 or 35 with high cell fertility, where the indication of IVF is only the tubal factor or patients who do not accept hormone stimulation for themselves. But of course, the more cells we get for fertilization, the higher the chances of getting quality embryos.