Principle of NT test for test tube infants
Test tube infant NT (Nuchal Translucency) is a fetal screening method used to assess the risk of fetal chromosomal abnormalities. NT examination assesses the possibility of fetal chromosomal abnormalities by measuring several parameters of the fetal neck, of which the most commonly measured parameter is the thickness of the zona pellucida in the fetal neck. NT examination can judge whether there is chromosomal abnormality in the fetus through the evaluation of these parameters, especially for Down syndrome and other common diseases with chromosomal abnormality.
The principle of NT examination is based on the relationship between the thickness of the zona pellucida in the fetal neck and fetal dysplasia. Normally, the zona pellucida in the neck of the fetus is very thin, because the normal chromosome number and structure of the fetus make the internal development of the fetus normal. Chromosome abnormalities, especially the abnormal number of chromosomes (for example, trisomy of Down syndrome), will lead to abnormal development in the fetus and thickening of the zona pellucida in the neck.
The uniqueness of this method is that it can be detected by ultrasound at an early stage to ensure that the fetus is irradiated. This is mainly due to the low cost of ultrasonic transmission, ease of operation and the shortcomings of the United States and China. In addition, through NT examination, fetuses with chromosomal abnormalities can be screened in the fetal period of the queen mother in order to make early intervention and treatment for fetuses with chromosomal abnormalities.
Steps of test tube baby NT examination
NT examination was conducted between 11-14 weeks of pregnancy. This inspection usually includes the following steps:
1. Ultrasonic examination: The doctor will use ultrasonic equipment to examine the fetus. The doctor will apply the gel on the mother's abdomen, and then place the ultrasonic probe on the abdomen to observe and measure the thickness of the fetal cervical transparent zone.
2. Data recording: The doctor will record the measured thickness of the zona pellucida and calculate it according to the mother's age, pregnancy and other factors to assess the risk of chromosomal abnormalities.
3. Genetic counseling: according to the NT examination results, the doctor will discuss the risk of chromosomal abnormalities with the couple. If the risk is high, the doctor may recommend further pathological examination, such as amniocentesis or umbilical cord blood test, to confirm whether the fetus has chromosome abnormalities.
Advantages of NT inspection
NT examination is widely used because of its advantages of non-invasive and early detection. The following are the advantages of NT check:
1. Non invasive: NT examination is a safe and harmless screening method, which does not require puncture or other invasive procedures. This allows most couples to opt for this test.
2. Early detection: NT examination can be carried out at the early stage of pregnancy, so that fetuses at risk of chromosomal abnormalities can be found as soon as possible. Early detection of chromosomal abnormalities can provide early intervention and treatment opportunities for the fetus.
3. High accuracy: NT examination is a relatively accurate screening method, which can largely predict whether the fetus has chromosome abnormalities. However, it should be emphasized that NT examination can not determine whether the fetus does have chromosome abnormalities, and can only make a risk assessment of chromosome abnormalities.
summary
Test tube infant NT examination uses ultrasound to measure the thickness of the zona pellucida in the neck of the fetus to evaluate whether the fetus has chromosome abnormalities. This examination has the advantages of non-invasive, early detection and high accuracy. Through NT examination, doctors can early identify fetuses at risk of chromosomal abnormalities and provide them with early intervention and treatment. However, it should be noted that NT examination can only make a risk assessment of chromosomal abnormalities, and cannot determine whether the fetus does have chromosomal abnormalities. Further examination may require confirmation.
