I. Necessity of fetal heart ultrasound examination
It is reported that congenital heart disease accounts for 8%~12% of births in China, which means that 120,000~200,000 children with congenital heart disease are born in China every year, of which about 20% are complicated and cannot be treated well by current treatments or are prone to die early after birth, which is one of the main causes of death in newborns and childhood. These bring heavy mental and economic burdens to families and society, and endless suffering to the affected children. Therefore, fetal echocardiography is an important part of prenatal ultrasound monitoring to predict fetal health, which is in line with our national policy of eugenics to improve the quality of birth population and reduce low age mortality.
Second, the main contents of fetal echocardiography investigation
Fetal heart malformation classification.
1, lethal malformations: hypoplastic left heart syndrome, pulmonary atresia, tricuspid atresia, single ventricle, single atrium, two-chambered heart, hypoplastic right heart, endocardial cushion defect, etc.
2. Non-lethal malformations: atrial septal defect, ventricular septal defect, ventricular defect combined with atrial defect, right-sided heart, thick arterial duct, etc.
The perinatal mortality rate of fatal cardiac malformations is high, the cost of surgical treatment is high, the efficacy is poor, and the average life expectancy is much lower than that of the normal population.
The purpose of fetal heart ultrasonography is to give prenatal diagnosis to these complicated, difficult to treat, and fetal heart prone to death at birth, so as to provide timely and correct scientific diagnostic basis for clinical diagnosis and timely diagnosis and treatment before and after birth.
III. Indications for fetal echocardiography.
Birth defects are caused by both genetic factors and environmental factors. The main causes of fetal heart malformation are related to genetic factors, pathogenic microorganisms, chemical and physical factors.
The risk factors for fetal congenital heart disease are both maternal and fetal.
(i) Maternal aspects.
1, the mother has various kinds of diabetes mellitus, connective tissue disease (such as systemic lupus erythematosus), chronic alcoholism.
2, early pregnancy with viral infections, colds, history of hyperthermia, history of medication (amphetamines, dalentin, potassium chloride, trimethoprim, etc.).
3, early pregnancy exposure to radiation, tungsten compounds, paints, pesticides, hair dyes or taking anti-cancer drugs, chemical agents, etc.
4, infected with viruses: rubella virus, cytomegalovirus, toxoplasma onset, human microvirus B19, etc.
5, advanced maternal age (age > 35 years), history of abnormal pregnancy, abortion, induction of labor, family history of congenital heart disease, history of congenital heart disease birth, etc.
(II) Fetal factors.
1, fetal combined with other organ malformation: such as hydrocephalus, abdominal wall cleft, etc.
2, chromosomal abnormalities.
3, fetal heart rate abnormalities: including bradycardia (less than 120 beats/min), tachycardia (more than 200 beats/min) and arrhythmia.
4.Fetal edema: including fetal subcutaneous and body cavity (chest and abdominal wall) effusion, pericardial effusion.
5.Abnormal amniotic fluid: too much amniotic fluid or too little amniotic fluid.
6.Fetal intrauterine growth retardation.
However, it has been reported that 1/3 of fetal heart disease is not accompanied by high risk factors for congenital heart disease. If echocardiography is done only for fetuses with high risk factors, it will cause 1/3 of fetal heart disease to be missed, so it is recommended to do one echocardiography for each fetus before delivery if possible (the price of fetal heart ultrasound is low at $130 per time and $155 per time for adults).
Fourth, the best time for fetal echocardiography.
The embryo develops to the second week and starts to form primitive blood vessels, the third week forms the primitive cardiovascular system and has blood circulation, the atria and ventricles are formed in the 7th~8th week, and the fetal heart structure is basically completed. Therefore, any external stimulation to the fetus during this period will affect the fetal cardiovascular development. However, the fetal heart is small in the early stage, and the fetal skeletal development in the late stage is affected by the acoustic shadow and fetal orientation. 22 weeks to 28 weeks is the best time for fetal echocardiography.