Symptoms of Down syndrome during pregnancy

Women should be tested for Down syndrome when they are about fifteen weeks pregnant, and this test is very important to avoid the occurrence of mentally retarded or other deformed babies. Pregnant women must also understand the symptoms of Down syndrome during pregnancy. For example, if the fetal movement is still weak after more than 20 weeks of pregnancy, there is a feeling of powerlessness, and the color ultrasound shows that the distance between the two eyes is abnormal, these are all things that need attention.

What are the symptoms of pregnant women with Down syndrome?

1. Fetal movement appears late, usually after 20 weeks of pregnancy, and the fetal movement is less, the ribs are weak, and the strength is not strong.

2. When the system color ultrasound displays the face, the distance between the eyes is abnormal.

3. The head is big, the double diameter top data is too large, but the limbs develop slowly.

4. The umbilical cord blood flow value (S/D during the examination) is abnormally large and there is no improvement after hospitalization.

What causes Down syndrome?

1. Causes

The incidence of Down syndrome is related to the mother's age during pregnancy. It is an abnormality of chromosome 21, and there are three types: trisomy, translocation and mosaicism. High maternal age and aging of the eggs are important causes of nondisjunction.

2. Pathogenesis

Trisomy can arise from the nondisjunction of chromosome 21 during meiosis of the parents' germ cells. Its occurrence mechanism is due to the nondisjunction of chromosomes in the meiosis of the parents' (mostly the mother's) germ cells. The older the pregnant woman is, the greater the possibility of Down syndrome (Table 1). In a family study of normal diploid parents who repeatedly gave birth to trisomy 21, it was found that the mosaic trisomy 21 cell line in the parents' germ cells and the uniparental disomy of maternal chromosome 21 were also the causes of trisomy 21. The translocation type can be inherited from one of the parents as a balanced translocation carrier of chromosome 21. Except for the chromosome translocation, the karyotype of the peripheral blood lymphocytes of the parents is mostly normal. The key part of chromosome 21 that produces the phenotypic characteristics of Down syndrome is 21q22.1~q22.2. Partial trisomy 21 that does not include this band does not present Down syndrome.

What is Down syndrome

The so-called Down syndrome is actually related to chromosomes. It is also called trisomy 21 and congenital idiocy. It is mainly caused by chromosomal abnormalities, that is, an extra chromosome 21.

It is the earliest chromosomal disease to be identified. 60% of affected children die or are miscarried in the early fetus. The survivors have obvious intellectual disability, special facial features, growth and development disorders and multiple malformations.