What Are the Prenatal Testing Procedures?

Update Date: Source: Network

There are many pregnancy examination items, mainly including B-ultrasound examination, measurement of uterine height and abdominal circumference, Down's screening, blood hCG examination, amniotic fluid aspiration, etc.

1. B-ultrasound Examination

B-ultrasound examination can only see the gestational sac after 5 weeks of pregnancy, and the detection rate of the gestational sac reaches 100% at 6 weeks of pregnancy. Embryo can be seen at 6-7 weeks of pregnancy, and primitive heart tube pulsation can be seen when the embryo diameter is 2mm at 49 days of pregnancy. The fetus begins to take shape at 8 weeks of pregnancy.

2. Measurement of Uterine Height and Abdominal Circumference

The uterine height and abdominal circumference of pregnant women are closely related to the size of the fetus. It is necessary to understand how much the uterine height and abdominal circumference increase every week. During prenatal examination, the uterine height and abdominal circumference should be measured every time to estimate the intrauterine development of the fetus, and at the same time, the intrauterine development of the fetus can be understood according to the curve of the uterine height pregnancy chart, whether there is developmental retardation or macrosomia.

3. Down's Screening

Down's screening is the abbreviation of prenatal screening for Down's syndrome. [1] The purpose is to determine the risk level of Down's syndrome in the fetus by testing the blood of pregnant women. If the Down's screening results show a high risk of Down's syndrome in the fetus, further confirmatory tests should be carried out.

4. Blood hCG Examination

hCG refers to human chorionic gonadotropin, which is composed of α and β dimer glycoprotein. After pregnancy, both blood and urine of women will contain hCG. Blood hCG examination can determine whether a woman is pregnant by measuring the hCG level in her blood.

5. Amniotic Fluid Aspiration

Also known as amniotic fluid aspiration, it is generally performed within 14 to 20 weeks of pregnancy. The method of amniotic fluid aspiration is to insert a thin needle through the abdomen and uterine wall of the pregnant woman under the guidance of ultrasound, enter the amniotic cavity, and extract amniotic fluid for comprehensive examination. Amniotic fluid aspiration is performed to screen for chromosomal abnormalities and reduce the birth rate of mentally retarded children.