🤔 Why is egg quality low?
A woman's reproductive health and the success of pregnancy are directly dependent on the quality of oocytes (eggs). However, low egg quality is often identified during EKO (IVF) procedures or natural conception. According to scientific data, one of the reasons for this may be genetic changes (polymorphism) in FSH and LH receptors.
It is precisely because of these changes that the ovaries do not respond sufficiently to hormones, and as a result, the quality of the retrieved eggs may decrease.
🔬 The complex structure and function of an egg
An egg (oocyte) is one of the largest and most complex cells in the human body. Its structure serves as the foundation for the future development of the embryo:
- Nucleus (Genetic material): Located in the center of the egg is the nucleus, which stores the mother's DNA information. Having a correct set of chromosomes is crucial for the formation of a healthy fetus.
- Cytoplasm and Mitochondria: The internal fluid of the cell (cytoplasm) is rich in nutrients. In particular, the mitochondria within it produce the energy (ATP) necessary for cell division in the first days after fertilization.
- Zona Pellucida: This is the protein shell surrounding the egg from the outside, which ensures that only one sperm enters and prevents polyspermy (multiple fertilization).
If there is a problem with any of these structures, particularly with mitochondrial energy or the elasticity of the shell, the egg is considered to be of poor quality.
🩸 Ovarian hormones and their role
The growth, maturation, and ovulation process of an egg are controlled by a complex chain of hormones produced by the pituitary gland and the ovaries:
1. Gonadotropic hormones (FSH and LH)
FSH (follicle-stimulating hormone), released from the pituitary gland, stimulates the growth of follicles in the ovaries. LH (luteinizing hormone) ensures the final stage of follicle maturation, ovulation (the rupture and release of the egg), and the formation of the corpus luteum.
2. Estrogen and Progesterone
Estrogens (mainly estradiol), produced by the ovary itself, thicken the uterine lining (endometrium) and help the follicle grow. The progesterone hormone, released after ovulation, prepares the uterus to receive a potential embryo and maintain the pregnancy.
🧬 Genetic changes: What is receptor polymorphism?
Sometimes, even if the hormone levels in a woman's body are normal, the ovaries do not "listen" to them. This is caused by genetic polymorphism — that is, small structural changes in the genes of the receptors that receive FSH and LH hormones.
Changes in FSHR and LHR genes
For example, certain polymorphisms in the FSHR (FSH receptor) gene (such as the N680S variant) reduce the receptor's sensitivity to the hormone. As a result, during EKO stimulation, the ovaries show a low response to standard drug doses, follicles develop poorly, and the retrieved oocytes are of low quality.
The genetically important aspect: LH receptors (LHR) are important not only for the maturation of eggs but also for the early developmental processes of the embryo. For this reason, changes in LH receptors can negatively affect the fertilization rate and the process of embryo implantation into the uterus.
🍏 The impact of external factors on the egg
Along with genetic factors, egg quality is also highly dependent on a woman's lifestyle. The ovarian microenvironment is extremely sensitive to external stress and toxins.
- Stress: Chronic stress increases cortisol and adrenaline hormones, worsening blood circulation in the ovaries.
- Poor nutrition and excess weight: A diet rich in sugar and unhealthy fats causes latent inflammation and insulin resistance in the body. This disrupts the function of the mitochondria within the oocytes.
- Harmful habits (Smoking, alcohol): Toxins in tobacco smoke damage the genetic apparatus of the eggs, increasing the risk of chromosomal mutations.
- Environmental factors: Substances such as heavy metals and bisphenol-A (BPA) released from plastic containers disrupt the endocrine system.
In modern reproductive medicine, taking genetic polymorphisms into account, EKO hormonal stimulation protocols are selected individually for each woman. This allows for the retrieval of high-quality eggs even from ovaries with low sensitivity to hormones.
📨 Source: Telegram: @reproduktolog_oqila