On August 20, 2021, the Standing Committee of the National People's Congress voted to pass a decision on amending the Population and Family Planning Law, which stipulates that the state advocates marriage and childbearing of appropriate age and eugenics, and a couple can have three children. With the implementation of the policy, the number of elderly women who require childbearing has been increasing, and the issue of fertility of elderly women has gradually become a hot spot in reproductive medicine.
Women's fertility gradually declines with age, and beyond 35 years old, it plummets. In our daily diagnosis and treatment activities, we generally refer to pregnant women over 35 years old as elderly patients.
So what kind of risks will be caused by the aging factor? First, egg quality is undoubtedly one of the most important hard conditions during natural conception or IVF, and it is closely related to the age of the patient. Elderly pregnant women are prone to chromosomal abnormalities, resulting in abnormal or distorted genetic material, so elderly pregnant women are prone to miscarriage. In the proportion of abortions in pregnant women at an advanced age, chromosomal abnormalities alone account for 50-80%, and advanced age will lead to an increase in fatal chromosomal abnormalities, and these chromosomal abnormal embryos are bound to miscarry.
According to genetic statistics, the younger the reproductive age of women in the reproductive age range, the easier it is to pass on the dominant gene to the offspring, and miss the optimal reproductive age, it is easier to pass on the defective gene to the offspring.
Second, the older the age, the easier the egg cells are to change, which will increase the chance of mutation of chromosomes, and the phenomenon of chromosomes not separating during cell division, manifested as the birth of children with chromosomal diseases, such as trisomy 21, cat syndrome, etc., as well as the birth of children with disease-causing micro-deletions and other congenital malformations, which brings great pressure and burden to the family and society.
So in the face of these problems, how can we avoid them? In recent years, especially in the past 1 or 2 years, with the development of molecular biology and the rapid development of detection methods, we have provided a strong technical guarantee to solve the above problems, which is the third generation of IVF technology that we often hear in daily life, that is, the preimplantation detection technology (PGT technology) that professionals say, it is based on ivy infant technology, sperm, eggs in vitro combined to form a fertilized egg, and after developing into an embryo, genetic testing should be carried out before transplantation to the uterus. The main test is whether the embryo has a genetically defective gene.
Select normally developed embryos to implant in the woman's uterine cavity to achieve the purpose of giving birth to a normal fetus and improve the rate of IVF carrying babies home. PGT is a new name defined by the International Health Organization in 2018, and its concept covers the previous PGD and PGS, and PGT is divided into PGT-A, PGT-M, PGT-SR, see figure below:
PGT-A is a preimplantation screening of aneuploid embryos, selecting a normal number of chromosomal embryos for transfer for at-risk couples. The goal of PGT-A is to identify chromosomally abnormal embryos so that they are not transferred, leaving unaffected embryos with a normal number of chromosomes to be selected for transfer, making it more likely to conceive a healthy baby.
PGT-SR is a preimplantation genetic test, such as chromosomal translocation, in embryos with chromosomal structural variations.
PGT-M refers to preimplantation genetic testing for single-gene genetic diseases. There are currently more than 10,000 single-gene diseases, including cystic fibrosis, spinal muscular atrophy, fragile X, ankylosing malnutrition and thalassemia.
For advanced-age patients with habitual miscarriage, PGT-A can improve their chances of a successful pregnancy, screening embryos for aneuploidy (missing or increased chromosomes), which is a major cause of miscarriage and implantation failure. The goal of PGT is to identify chromosomally normal embryos for transfer, thereby significantly increasing the success rate of the test tube.
In summary, for the elderly women with fertility requirements should be combined with their own situation to choose the method of adaptation for scientific and reasonable screening, in order to achieve the goal of normal birth, finally, it needs to be emphasized that women must be born early and eugenic at the appropriate age of childbearing, do not waste valuable time to cause regrets.