Generally speaking, combined serological methods are used to screen for Down syndrome. The process is to draw the peripheral blood of pregnant women and then extract the serum. Pregnant women do not have to fast during this process. During the serum examination, the concentration of alpha-fetoprotein (AFP) and serum chorionic gonadotropin (HCG) in the expectant mother\’s serum will be detected, and \”risk factors\” and the pregnant woman\’s weight will be calculated based on the expected date of delivery, age, and gestational age. This way 60-70% of congenital fools can be detected. To achieve the purpose of \”prophet\”.
At the same time, this examination can also detect high-risk pregnant women such as neural tube defects, trisomy 18, and trisomy 13. However, if the serological test is positive, an amniotic fluid test is also required to confirm the diagnosis. It should be noted that fasting is not required for Down syndrome examination, but it is not advisable to eat too much during the examination. If fasting is required for other tests on the day, you can prepare as usual.
What are the screening programs for Down syndrome?
Down syndrome screening generally checks maternal serum markers, including concentrations of alpha-fetoprotein (AFP), human chorionic gonadotropin (-hCG), free estriol (uE3), and inhibin A (InhibinA) . Divided into the following steps:
First, perform the first phase of Down syndrome screening. The risk of fetal Down syndrome is estimated by ultrasound and blood draw at 9-13 weeks of pregnancy; in the second phase of screening, blood is drawn at 15-20 weeks of pregnancy. Estimation is made based on the results of the first period. If the risk is high, you can do chorionic villus sampling, which is an invasive test that requires careful communication with your doctor, or amniocentesis, which is also invasive but has less risk than chorionic villus sampling. Through the above procedures, you can generally know more accurate results.
When is the best time to screen for Down syndrome?
Generally speaking, the best time for Down syndrome screening is between 15 and 20 weeks of pregnancy. But the specifics can be determined according to the actual situation.
Down syndrome screening includes two periods of examination, early pregnancy screening at 9-13 weeks of pregnancy, and second-trimester screening at 14-21 weeks of pregnancy, which is generally more common in the second trimester. After women learn that they are pregnant, they need to go to the hospital for regular check-ups. Not only can they understand the physical condition of the expectant mother, but they can also keep abreast of the development of the fetus. At 12 weeks of pregnancy, you need to check your weight, blood pressure, listen to fetal heart rate, uterine size, blood and urine tests, and understand your past medical history. Wait until about 13 to 16 weeks, the second trimester, to be screened for Down syndrome.
If detected in time, it may be corrected through early intervention, and the child will be like a normal person after birth.
Down syndrome screening considerations
Every pregnant woman may be pregnant with a child with Down syndrome, so prenatal screening for Down syndrome should be performed. Down syndrome screening is performed at 15-20 weeks of pregnancy by combining serumMedical and B-ultrasound examination, combined with comprehensive risk assessment of pregnant women’s age, weight, gestational age, medical history, etc. Does Down syndrome screening require fasting? Fasting is not required for Down syndrome screening. Here are the following points about Down syndrome screening:
1. Screening time: The best time is 15-20 weeks of pregnancy.
2. Economical and convenient, no harm to the fetus. Although the results of Tang screening cannot accurately determine whether the fetus is stupid, after all, it is the most economical, simple and non-destructive testing method to determine whether the fetus is stupid. If the results are found to be high risk, amniocentesis may be performed.
3. Screening methods: Combined serological methods are often used to screen for Down syndrome. Collect the peripheral blood of pregnant women, extract serum (without fasting), detect maternal serum alpha-fetoprotein (AFP) and serum chorionic gonadotropin (HCG) concentrations, combine the expected date of delivery, maternal age and gestational age, and calculate risk factors based on weight.\” 80% of congenital fools can be detected.
4. Cost: About 100 yuan, but different hospitals in different places have different standards.
5. Preparation before the examination: Down syndrome screening does not require fasting, but it is related to the menstrual cycle, weight, height, accurate gestational age, and gestational age. Before screening, pregnant women need to provide more detailed personal information, including date of birth, last menstrual period, weight, insulin-dependent diabetes, twins, smoking, abnormal pregnancy history, etc. Risk rate statistics since screening need to be corrected for the above factors, and it is also important to fill in the test form before drawing blood.
6. Down syndrome screening is temporarily not applicable to IVF and twin pregnancies.