Poor egg shape

Poor egg morphology is related to the developmental environment of a woman's ovaries and uterus. If the secretory function of the ovaries decreases and the uterus is infected, the quality of the eggs will be affected. Therefore, when the egg morphology is poor, it cannot be used for fertilization to avoid causing a deformed fetus. As for the causes of poor egg morphology, you can learn about the contents of this article.

1. Egg appearance

When observed under a microscope, the appearance of a mature egg (MⅡ egg) includes: zona pellucida, first polar body, oocyte, perivitelline space and other parts.

(1) Zona pellucida: It is a homogeneous semipermeable membrane that wraps around the oocyte and polar body. The eggshell that looks like an egg is often called "the egg sister's little cotton-padded jacket." Protect the egg to complete the normal fertilization process and maintain the microenvironment for early embryo development.

(2) First polar body: After asymmetric meiosis, a very large oocyte and a very small polar body are formed. (Note: After the egg and sperm combine for fertilization, the oocyte will also release the second polar body!)

(3) Oocyte: It is the most important part of the egg. The beginning of life is mainly initiated by the oocyte. The oocyte contains the cell membrane, cytoplasm (plasma) and nucleus. The cytoplasm contains many cellular microstructures, which are very complex and rich.

(4) Periovitelline space: During ovulation, the oocyte occupies most of the volume within the zona pellucida. After fertilization, the oocyte shrinks and a gap forms between the zona pellucida and the oocyte.

So, what should a well-developed egg look like?

Qitai International pointed out that under an ordinary optical microscope, the appearance of the egg should be: moderate in size; the cytoplasmic granules are uniform and smooth, without vacuoles, refractive pigment granules, or sticky white spot-like changes. To put it in an analogy, just as good skin is delicate, uniform, and smooth, if there are spots on the skin and it looks bumpy, it is naturally not good skin; the perivitelline space is of moderate size, without foreign matter or debris; the polar bodies are of moderate size, round or oval, without breakage; the zona pellucida is spherical in shape, smooth, with moderate and uniform thickness, without serrated changes.

2. The egg looks abnormal

The main manifestations of abnormal appearance are:

(1) Extracytoplasmic abnormalities of the oocyte: fragmentation, enlargement or degeneration of the first polar body, thick or dark zona pellucida, enlarged perivitelline space, and unsightly oocyte shape, such as ellipsoidal oocyte;

(2) Abnormalities in the cytoplasm of the egg: coarse particles in the cytoplasm, the appearance of a large number of vacuoles in the center of the cytoplasm, etc. Some abnormal eggs are brown as a whole. There are also special cases such as giant eggs and two connected eggs in a single follicle.

So, what does it mean clinically if the egg looks bad? What impact will it have on "test tube babies"? Many studies have shown that abnormal egg morphology will affect the success rate, and these impacts are multifaceted.

1. Affect the fertilization rate of eggs;

2. Affect the quality of the embryo. This abnormal oocyte will significantly reduce the embryo score and blastocyst formation rate after fertilization. ;

3. Affect the pregnancy rate of IVF treatment;

In short, the outcome of assisted reproductive technology treatment is closely related to the quality of the eggs obtained. So far, there is no objective indicator to determine the quality of eggs, and they can only be evaluated by morphological appearance. Embryologists at reproductive centers often assess the appearance of oocytes to help determine the developmental potential of eggs. They combine the appearance and scores of various developmental stages, such as eggs, fertilized eggs, cleavage-stage embryos, and blastocysts, to select the best embryos for transplantation and improve the success rate of treatment.