If, in the initial stage, the fertilized egg has abnormal development, it will automatically terminate its development, which is called "embryo abortion", which is the stage before spontaneous abortion. If the embryo is expelled from the body by the mother for self-protection, it is called spontaneous abortion, and if it fails to be expelled and stays in the uterine cavity, it is called missed abortion.
The main reasons are endocrine disorders, uterine abnormalities, chromosome problems, immune factors, reproductive tract infections, environmental factors and so on.
Symptoms If the embryo stops, the mother will have a series of changes to facilitate its excretion. First of all, the decrease of estrogen and progesterone, the immune rejection of the embryo by the body, and the formation of thrombus between the mother and the embryo may lead to vaginal bleeding. The bleeding at this time is called threatened abortion, which is a signal that the embryo will be excreted. This needs to be distinguished from vaginal bleeding during normal embryo development. If vaginal bleeding can be manifested as the normal development of the embryo due to local blood vessel rupture, the bleeding at this time will not lead to the expulsion of the embryo from the body, so it cannot be called threatened abortion.
There will be short-term lower abdominal pain during the process of embryo expulsion. Early pregnancy reaction can be alleviated after embryo abortion, but the early pregnancy reaction itself will vary from individual to individual, so early pregnancy reaction can not be used to judge embryo development. Most pregnant women have no obvious symptoms after the fetus stops developing, and the diagnosis can only be made by hormone examination combined with ultrasonic detection in the first trimester.
diagnose
The patient has a history of menopause, and whether she sees redness or not, she should have a B-ultrasound examination in the first trimester to avoid missed diagnosis of fetal arrest. B-ultrasound monitoring the development of embryo and fetus. If there is no gestational sac at ≥6 weeks, or if there is a gestational sac but it is deformed and shriveled, if the gestational sac is ≥4cm but there is no embryo, and if the embryo (head length and arm length) is ≥4~5mm, there is no fetal heart, it can be judged that the embryo and fetus have stopped. In addition, the determination of blood β-hcG is also helpful for the diagnosis of fetal arrest. If ≥5 weeks, blood β-HCG
cause analysis
Abortion refers to the termination of embryonic development in early pregnancy for some reason. B-ultrasound examination showed that gestational sac's inner tube bud or fetus was not formed, and there was no fetal heart beat, or gestational sac withered. Clinically it belongs to the category of abortion or stillbirth. There are many reasons for abortion, more than 90% of which are related to the abnormality of the embryo itself, and a few cases are related to luteal insufficiency, hyperprolactinemia, thyroid dysfunction and diabetes.
1, endocrine disorder
Embryo implantation and sustained development depend on the coordination of complex endocrine system, and any link disorder may lead to abortion. Early embryonic development requires three important hormone levels, one is estrogen, the other is progesterone and the other is human chorionic gonadotropin. As a mother, if endogenous hormones are insufficient to meet the needs of embryos, it may lead to miscarriage and abortion. One of the most common is luteal insufficiency, which can cause endometrial development retardation and short luteal phase, thus affecting fertilized eggs implantation or early pregnancy abortion. Luteal insufficiency is often accompanied by other gland dysfunction, such as hyperthyroidism or hypothyroidism, diabetes, relative increase of androgen and hyperprolactinemia. These factors are not conducive to embryo development and are closely related to abortion.
2. Abnormal uterus
Both the intrauterine environment and the overall uterine environment may affect the embryo. The internal environment is the endometrium. Too thin or too thick will affect implantation. Abortion caused by uterine defect accounts for about 10%~ 15%. Common (1) congenital anomalies of Mullerian duct include unicornuate uterus, bicornuate uterus, septate uterus, bicornuate uterus, etc., which leads to uterine stenosis and limited blood supply. Abnormal uterine artery development can lead to unsynchronized decidualization and abnormal implantation. (2) Intrauterine adhesion is mainly caused by intrauterine trauma, infection or placental tissue residue. It hinders normal decidualization and placenta implantation. (3) The decrease of blood supply caused by hysteromyoma and endometriosis leads to ischemia and venous dilatation, and the dyssynchrony of decidualization, abnormal implantation and hormonal changes caused by hysteromyoma can also lead to pregnancy failure. (4) Abnormal cervical development caused by congenital or traumatic relaxation of the cervix and treatment with diethylstilbestrol often leads to abortion in the second trimester.
3. Chromosome problem
If the chromosome is abnormal, it will also lead to embryonic hypoplasia and early abortion. Chromosome abnormalities include quantitative and structural abnormalities. Quantitative anomalies can be divided into aneuploid and polyploid. The most common abnormal karyotype is aneuploid trisomy, 16- trisomy accounts for 1/3, which is often fatal. 25-67% of 2 1- trisomy, 4-50% of 13- trisomy, and 6-33% of 18- trisomy are bound to miscarry. There are haploids (45, XO), and tetraploid embryos do not develop due to abnormal cleavage. Structural abnormalities include deletion, balanced translocation, inversion and overlap.
The balanced translocation of one spouse's chromosome easily leads to chromosome abnormality in the embryo, thus causing embryo abortion. The mechanism of embryo chromosome abnormality is that chromosome fragments are easy to be lost or repeated when couples mix chromosomes, which leads to abnormal chromosome development of fertilized eggs, which can lead to abortion, stillbirth and deformed children. Therefore, couples with chromosome translocation need prenatal diagnosis in the second trimester to prevent the birth of children with chromosome diseases. Chromosome abnormalities, in theory, have a chance to give birth to normal karyotypes and carriers' babies. Prenatal diagnosis should be made for these couples to ensure normal babies.
Abnormal genetic material carried by sperm will lead to embryo abortion, but abnormal sperm refers to the appearance of sperm rather than the genetic material carried by sperm. Morphological evaluation of sperm is used to evaluate male fertility. Abnormal sperm refers to the sperm that has no chance to meet the egg in the natural state, so it doesn't matter whether abnormal sperm carries the genetic material normally. So abnormal sperm has nothing to do with spontaneous abortion. Sperm deformity rate is a percentage of semen evaluation index, which must be evaluated in combination with the total number of sperm.
4. Immune factors
Embryo abortion caused by immune factors is rare and can not be diagnosed clearly. Immunological theory refers to the rejection of the fetus by the mother after pregnancy, because the fetus is a combination of parents' genetic materials, and the mother can't be exactly the same. The immune incompatibility between the mother and the fetus leads to the rejection of the fetus by the mother. But at present, we have no way to know whether the reason for stopping childbearing is because the mother rejects the embryo. But logically speaking, if the embryo is rejected by the mother, it should happen earlier, not after the fetal heart. Blocking antibody is only a control index after immunotherapy and cannot be used as the etiological diagnosis of embryo abortion. Most women are negative for blocking antibodies during non-pregnancy, and only a few women can detect blocking antibodies even in the second trimester of pregnancy.
5, reproductive tract infection
In addition to the above factors, early pregnancy and abortion caused by infection have attracted more and more attention from scholars at home and abroad. Severe TORCH infection in early pregnancy can lead to embryo death or abortion, and mild infection can also lead to embryo malformation. Studies have shown that cytomegalovirus can cause expired abortion, intrauterine death and so on. After maternal infection, pathogens can infect the placenta through blood, causing damage to chorion and capillary endothelium, destroying the placental barrier, and pathogens enter the fetus, leading to abortion, embryo stagnation and fetal malformation. In recent years, many studies have shown that mycoplasma infection may be related to embryo stagnation, but some scholars have suggested that mycoplasma can be a normal flora of human body, and mycoplasma found in repeated abortion people can only be called mycoplasma existence, not mycoplasma infection.
6. Environmental factors
The change of physiological state during pregnancy has greatly changed the absorption, distribution and excretion of therapeutic drugs and various environmentally harmful substances by the mother. Embryo is extremely sensitive to the influence of therapeutic drugs and environmental factors in the early stage of development. At this time, various harmful factors can lead to embryo damage or even loss. Many drugs and environmental factors are important factors leading to early embryonic death or fetal malformation. Environmental hormones can directly act on the endocrine regulation system of the central nervous system, causing reproductive hormone secretion disorder, decreased reproductive rate and abnormal embryo development. There are many environmental factors that cause abortion, including physical factors such as X-ray, microwave, noise, ultrasound and high temperature. Heavy metals such as aluminum, lead, mercury and zinc affect the implantation of fertilized eggs or directly damage embryos, leading to abortion. Dioxin, carbon disulfide, anesthetic gas, oral hypoglycemic drugs and other chemicals can interfere with and damage reproductive function, leading to embryo abortion, stillbirth, deformity, developmental retardation and dysfunction. And bad living habits such as smoking, drinking, coffee, drugs and some drugs all affect early embryo development.