Prenatal screening for Down syndrome is a screening program that every woman undergoes during childbirth. Some pregnant women must undergo prenatal check ups because some prenatal check ups require fasting and are ineffective after breakfast. Many women are not clear about how to draw blood for Down syndrome screening and do not know what the blood drawing process is. So, how to draw blood for Down syndrome screening?
Down syndrome screening is divided into two stages: early pregnancy screening from the 9th to 13th week of pregnancy; The 14th to 21st week and 6th day of pregnancy are called mid-term pregnancy screening. Pregnant women can generally receive screening results within one week after blood draw, whether in the early or middle stages. If the result is high-risk, there is no need to panic because the diagnosis at this time is not yet clear and further diagnosis is needed.
Screening for Down's disease during the first pregnancy: This examination mainly uses two screening methods, "ultrasound" and "blood draw", during the 10th to 13th week of pregnancy. In addition, blood tests and measurements of maternal serum can be used to assess the risk of Down syndrome in fetuses.
Second screening for Down syndrome during pregnancy: Pregnant women undergo blood tests from weeks 15 to 20, and the hospital will detect the main components in the serum and calculate the risk of Down syndrome in the fetus based on the age, gestational weeks, and weight of the pregnant woman.
Choroidal sampling: Doctors say that when pregnant women want to undergo this examination, necessary consultation and discussion must be done, as this examination requires extracting some cell samples from the developing placenta.
Amniotic membrane puncture examination: This also requires detailed discussion with the doctor, but its risk is lower than that of chorionic sampling. The doctor said that by extracting amniotic fluid from the amniotic cavity of a pregnant woman's uterus and testing it, we can determine whether the fetus has abnormal chromosomal status, thereby knowing if it may have Down syndrome. It takes 14 days to know the results, with an accuracy rate of up to 99%.
