A very common question that couples ask is whether the quality of their eggs affects the result of in vitro fertilization.
The quality of the eggs, even when described by embryologists as “poor”, is not usually prohibitive for the outcome of in vitro fertilization. Except in cases where the woman is in an extracorporeal natural cycle (so the poor quality egg is the only one we have) we choose some of the eggs that have a better morphology, in order to fertilize and transfer them. Even if all the eggs are of “poor” quality, there is a chance of pregnancy, but they are generally lower.
Egg maturation and success of in vitro fertilization
During ovulation and before fertilization, embryologists evaluate the degree of maturation of the eggs. The reason for a failed attempt is often the high percentage of immature eggs obtained during egg retrieval. The question then is whether a different protocol that will allow more time to be given to stimulate the ovaries will help to fully mature the eggs in a later attempt. In fact, immature eggs are rarely the result of inadequate arousal if ultrasound and hormonal tests are performed according to proper female protocols. Inadequate egg maturation is usually caused by some ovarian dysfunction, reduced egg supply or may be due to polycystic ovary syndrome (PCOS).
Egg quality
In order for an egg to be considered good quality and therefore fertilizable, it must first be mature, in the metaphase stage II (MII). The stage of metaphase II indicates that the process of egg maturation has been completed. In this final stage of its maturation, the first reductive division takes place, ie the pairs of homologous chromosomes are divided into two new cells. These two cells are unequal in size. The large cell is the egg that contains almost all of the cytoplasm.
It is what will be fertilized. The small cell, although it also has half the number of homologous chromosomes, contains minimal cytoplasm, is not fertilized and is called the first polar body. Thus an egg that is fully mature, i.e. in metaphase II, has 23 chromosomes and has a clean and homogeneous cytoplasm. The reason why this reduction of chromosomes takes place and instead of 46 we have 23, is that in fertilization the sperm will bring the other 23 that are necessary to create a normal embryo with 46 chromosomes. Size is related to the quality of the egg and in extreme cases of oversized or small eggs, there are often abnormalities. If the egg has not reached the final stage of maturity, it is in an intermediate stage of maturity, which is the stage of metaphase I, characterized by the absence of a polar body and having an extensive and non-compact complex of granule cells. An even more early stage of maturation is the stage of prephase I or germ cell vesicle (GV).
The characteristics of good quality egg
Generally a good quality egg should:
To be in metaphase stage II, ie to be mature.
To have a smooth and spherical shape.
To have a diameter of about 100-120μm or together with the transparent film
to have a diameter of up to about 150μm.
Its cytoplasm should be “clean” and uniform.
Have a small perilectal space (ie the space between the cytoplasm and the transparent zone to be small, not enlarged).
What an egg should NOT have to be of good quality:
Dark color and multi-grain cytoplasm.
These eggs usually show a low rate of fertilization and, if fertilized, a low rate of proper embryonic development.
Many or large vacancies. In case we see that the eggs have many or large cavities, in the laboratory we should choose microfertilization (ICSI) as a method of fertilization, as this increases the chance of fertilization.
Often these eggs are associated with reduced pregnancy rates. Large perilectal space. Fragments of polar bodies. Irregular shape.
What should the couple do if the eggs are of poor quality?
A complete history must first be obtained. The couple should discuss with the experts (gynecologist, endocrinologist, embryologist, geneticist) the following:
The levels of female hormones.
The history of infertility
Possible history of autoimmunity
The ovarian stimulation protocol used If in the past there were similar results in egg quality
The response to the stimulation protocol, such as ultrasound findings, estradiol measurements, etc.
Vitamin D levels
Also check AMI and inhibin B (inhibin B) by specialists who can evaluate the quality and quantity of eggs
With all this information in our hands, we can advise the couple on what needs to be done to improve egg quality or if we think we should move on to other solutions, such as egg donation. Each case is completely separate and the approach, but also the treatment must be completely personalized.
Note: Our center investigates the quality of the genital material of both the woman and the man so that when and if she needs to enter the IVF process, she can do it with high. We can help you online consultation by skype or viber at email: [email protected]
SOURCE: http://ivfgreece.gr/poiotita-oarion-exosomatiki/
