(1) endocrine disorders:Embryo implantation and continuous development depend on the complex endocrine system to coordinate with each other,
(1) endocrine disorders:
Embryo implantation and continuous development depend on the complex endocrine system to coordinate with each other, any one link is abnormal, can cause abortion. When the early embryo development, need three important hormones, one is an estrogen, progesterone, a human chorionic gonadotropin, as a parent, endogenous hormone deficiencies, it can not meet the needs of the embryo, it is possible to cause the embryo growth arrest and abortion. One of the most common is the corpus luteum dysfunction, luteal insufficiency can cause endometrial retardation and luteal phase short, thus affecting the fertilized egg implantation, or early pregnancy abortion. Luteal dysfunction is often accompanied by other glands dysfunction, such as hyperthyroidism or hypothyroidism, diabetes, androgen relative increase in disease and hyperprolactinemia, these factors are not conducive to the development of embryos, and is closely related to abortion.
(2) immune factors:
The embryo or fetus of a pregnant uterus is an allogeneic transplant because the fetus is the parent of the genetic material of the combination and the mother can not be exactly the same. Maternal fetal immune disorder caused by maternal fetal rejection. A common autoimmune disease in systemic lupus erythematosus, scleroderma and mixed connective tissue disease, dermatomyositis. The second is the issue of reproductive immunity, if we ourselves with a certain antibody, it may affect the development of embryos. In fact, the detection of antibodies in each hospital is not the same, the doctor's views are not the same, from our research perspective, that there are four factors, one is the anti sperm antibodies, if any, are likely to resist sperm egg binding; second, anti endometrial antibodies, if present the anti endometrium antibody, may affect the development of embryos, embryos resist anti ovary antibody; third is, if there is, will affect the quality of ovum; fourth is called anti hCG antibody, this hormone is actually the sperm egg binding is an important hormone after seven days secretion, but if itself has such antibodies, will resist hormone secretion, it may cause embryonic diapause.
(3) abnormal uterus:
The internal environment of the uterus and the overall environment of the uterus may have an impact on the embryo. Internal environment is the endometrium, if too thin, too thick will affect the implantation. Due to uterine defects caused by abortion accounted for about 10%~15%, common (1) congenital Mullerian duct abnormalities, including single horn uterus, double uterus and double horn uterus caused by narrow, blood supply is limited. Abnormal uterine artery can lead to synchronization and abnormal growth of decidua. (2) intrauterine adhesions, mainly caused by intrauterine trauma, infection or residual placental tissue, cause intrauterine adhesions and fibrosis. Hinder the normal decidua and placenta implantation. (3) the hysteromyoma and endometriosis caused by reduced blood supply in ischemic and vein dilation, decidualization asynchrony, hormone abnormalities and the changes caused by the planting of myoma can also cause the failure of pregnancy. (4) received diethylstilbestrol treatment caused by cervical dysplasia often caused mid pregnancy abortion or congenital injury of cervical relaxation and in the tyre.
(4) the problem of chromosomes:
If the abnormal chromosome would cause the embryo development and early abortion. Including the number of chromosome abnormalities and structural abnormalities, abnormal number divided into aneuploidy and polyploidy, abnormal karyotype was the most common triploid, and trisomy 16 and accounted for 1/3, often fatal. 21 trisomy 25~67%, trisomy 13, one of the 50%, in the 18 trisomy 6~33% inevitable abortion. The other is haploid (4SX), tetraploid due to anomalies of embryo cleavage and development. There are some structural abnormalities, such as balanced translocation, inversion and overlap. Balanced translocation is the most common chromosomal abnormality. The current study of chromosomes that deals with the pairing, exchange, and separation of chromosomes to form gametes. If the zygote has unusual, causes can not be normal development, can lead to miscarriage, stillbirth and congenital deformities, therefore, need to do prenatal diagnosis to prevent the birth of children with chromosome. There is no effective treatment for abortion and fetal abortion caused by chromosome abnormality, which can only be used in prenatal genetic counseling and diagnosis. For chromosomal abnormalities, in theory, both the delivery of normal karyotype and the opportunity to carry the baby, these couples do prenatal diagnosis, to ensure the normal birth of infants. Of course, the present study also showed that the chromosomes of both spouses are normal, but the formation of gametes and embryo development in the process of chromosomal abnormalities. As women older than 35 years old, prone to oocyte aging, chromosome separation, cause chromosomal abnormalities; abnormal sperm, such as the bulk of sperm abnormality in most diploid and polyploid embryos formed after fertilization leads to abortion. Adverse environmental effects, such as toxic chemicals, radiation, high temperature can also cause embryonic chromosomal abnormalities. Therefore, the prevention of chromosomal abnormalities due to fetal abortion is the key to regulating the body of both sides of the couple, so that the normal functioning of the organs, yin and yang balance, preferred and pregnant, and away from the bad environment.
(5) genital tract infection:
In addition to the above factors, infection induced abortion in early pregnancy has been paid more and more attention by scholars at home and abroad. Severe TDRCH infection in early pregnancy can cause fetal death or abortion. Studies have shown that cytomegalovirus can cause premature abortion, fetal death, etc.. Maternal infection occurs after the pathogen can pass through the blood placental infection caused by exercise, chorion and capillary endothelial damage, destroy pathogens into the human fetal placental barrier, cause abortion, embryonic and fetal malformation figure. In recent years, many studies have shown that mycoplasma infection is related to the development of the embryo, and the positive rate of cervical secretion mycoplasma infection is significantly higher than that of normal women.
(6) environmental factors:
Pregnancy physiological status change, the mother changed the absorption, distribution and excretion of drugs and various environmental harmful substances, in the early development of embryo, effects of drugs and environmental factors are extremely sensitive to the various harmful factors can lead to fetal damage, even lost. Many drugs and environmental factors are important factors leading to early embryonic death or fetal malformation. Environmental hormones can directly act on the central nervous system, causing the disorder of reproductive hormone secretion, the decrease of reproductive rate and abnormal development of embryo. Due to various environmental factors of abortion diversity, including X ray, microwave, ultrasonic, noise, high temperature and other physical factors, and heavy metals aluminum, lead, mercury and zinc affect implantation of fertilized eggs or embryos caused direct damage to abortion. All kinds of chemical drugs such as Australia and two chloride, carbon disulfide, anesthetic gas, oral anti diabetic drugs such as reproductive function damage caused by interference, and embryo abortion, fetal death, malformation, growth retardation and dysfunction. And bad habits such as smoking, alcohol, coffee, drugs, drugs and other factors affect the development of early embryos.