The death of a fetus in the uterus after 20 weeks of gestation is called stillbirth, or intrauterine fetal death. Since about half of all stillbirths show no signs at all, most parents lose their fetus completely unaware.
Causes of stillbirth
The incidence of stillbirth has been reported to be about 1/200, and the incidence of stillbirth has not decreased significantly despite continuous medical development, probably because of the complex etiology of stillbirth and the difficulty of taking targeted preventive and curative measures in some cases where the cause of death is unclear. Stillbirths are reported to be the first or second cause of perinatal death at home and abroad. The common causes of intrauterine fetal death are as follows: Yao Xiaoying, Department of Family Planning, Obstetrics and Gynecology Hospital, Fudan University
1. Maternal factors of stillbirth
The occurrence of stillbirth is related to economic status, education level, the age of pregnant women, pregnant women who do not perform prenatal checkups or only irregular prenatal checkups stillbirths may increase.
(1) Genetic factors: hereditary diseases are one of the common causes of stillbirth. Among them, monogenic genetic diseases, polygenic genetic diseases, chromosomal aberrations and placental restrictive chimerism can cause stillbirth, malformation or other congenital defects.
(2) Obstetric-specific infections: Obstetric-specific infections are a group of infectious diseases suffered by pregnant women during pregnancy, whose pathogens can be transmitted vertically to the embryo or fetus, causing damage to it. Obstetric-specific infections causing adverse pregnancy outcomes have become a harsh fact and are a growing concern. There are many pathogens that cause intrauterine infections resulting in adverse fetal outcomes, including viruses, bacteria, mycoplasma, chlamydia, and protozoa. These infections are characterized by mothers who often do not show obvious symptoms, but can cause fetal malformations, miscarriage, stillbirth, stillbirth, or neonatal central nervous system damage.
(3) Occupational, environmental and toxic factors: Some literature reports that the incidence of miscarriage, stillbirth and stillbirth is significantly higher after pregnancy of female workers in long-term aluminum work, so aluminum work has adverse effects on reproductive function and offspring. Synthetic rubber industry, welding industry, the incidence of stillbirth, stillbirth significantly higher. Environmental pollution caused by petrochemical plants is one of the factors that affect pregnancy outcomes. Some drugs and poisons can cause fetal damage through the placental barrier, and the incidence of stillbirth can be increased by smoking, drug use, alcohol abuse and exposure to pesticides. In addition, high-dose radiation exposure can also cause malformation, miscarriage and stillbirth.
(4) Pregnancy complications and comorbidities: the impact of pregnancy complications and comorbidities on the outcome of pregnancy depends on the severity of the condition.
2. Fetal factors of stillbirth
About half of the stillbirths are related to fetal factors, and fetal malformation takes the first place in this factor. The occurrence of fetal malformation is related to genetics, environment, toxic exposure, infection, etc.
3.Placental factors of stillbirth
The placenta is an important organ for the mother to supply nutrition and oxygen to the fetus, and serious abnormalities in the morphology and function of the placenta can lead to stillbirth.
(1) Abnormal placenta morphology, such as rotund placenta, membranous placenta, small placenta, all due to the reduction of the area of maternal and fetal nutrient exchange, the fetus lack of oxygen and other nutrients, stillbirth occurs.
(2) Placental abnormalities such as aging and decreasing function of the placenta in late pregnancy, which reduces the nutrients and oxygen transfer to the fetus and makes it easy for fetal distress and intrauterine death to occur.
(3) Placental tumors such as placental parenchymal hemangioma, benign capillary hemangioma and large diffuse hemangiomatosis, due to the reduction of blood entering the fetus, the fetus is prone to death due to hypoxia.
(4) Placentitis Inflammation causes placental congestion, edema and exudation, which affects the exchange of substances between mother and child causing stillbirth.
4.The umbilical cord factor of stillbirth
The umbilical cord is an important link to maintain the life of the fetus. The most common umbilical cord lesions associated with fetal death in utero are cord entanglement, true knot, cord hematoma and cord vascular embolism, which block fetal blood circulation and cause fetal death due to intrauterine hypoxia. Prenatal prediction of fetal death due to acute hypoxia caused by umbilical cord factors is difficult.
Prevention of stillbirth
Congenital malformations can lead to stillbirth. Folic acid supplementation during pregnancy preparation can reduce the chance of fetal neural tube defects (including anencephaly, cerebral bulge, and spina bifida), one of the few preventable congenital malformations, including fetal death.
Treating maternal illnesses: Many chronic maternal illnesses, such as hypertension, diabetes or thyroid abnormalities, can increase the chance of fetal death, so relevant tests should be performed before pregnancy, and if such problems are found, they should be treated first and then conceived after the condition has stabilized.
Avoid environmental toxins: Environmental toxins can increase the chance of fetal death, such as smoking, use of drugs such as heroin, environmental pollutants or toxins, etc. should be avoided as much as possible.
Adjust your work and rest, eat a balanced diet, enhance nutrition, and maintain a good state of mind.
Pay attention to epidemic diseases: there are some infectious diseases that can not only cause fetal death, but also leave serious sequelae even if the fetus survives. During the epidemic period, try to avoid going to public places to avoid being infected.
The pregnancy check-ups should be done on time, so that problems such as gestational diabetes or gestational hypertension can be detected early and treated promptly, which will not only reduce the chance of fetal death but also ensure the safety of the mother.
The history of previous stillbirths should be taken into account and the cause of the stillbirth should be identified if possible: try to avoid or treat the cause of the last stillbirth in the second pregnancy. The fetal movement count is one of the world’s most recognized means of self-monitoring for pregnant women. Learning to count fetal movement and finding abnormal fetal movement should be promptly consulted for early detection and causal treatment. It is also possible to reduce the occurrence of stillbirth in late pregnancy by terminating the pregnancy at the right time.
The reason is that some stillbirths cannot be prevented even if the cause is clear. However, what pregnant mothers can do is not to smoke or drink, stay away from toxins, keep a good mood, have regular maternity checkups, pay attention to fetal movements, and notify the doctor of any abnormalities.