Down Syndrome Screening Test

Comprehensive Down Syndrome Screening Methods

Differed in the weeks of pregnancy, the screening methods for Down syndrome can be divided into first-trimester Down syndrome screening and second-trimester Down syndrome screening. The first-trimester Down syndrome screening primarily provides pregnant women with early screening for understanding the well-being of their babies. If the first-trimester Down syndrome screening was missed early on in one’s pregnancy, the second-trimester maternal serum screening for Down syndrome can be chosen instead. The currently common Down syndrome screening methods are summarized in the following table, briefly described as below:

Table of Down Syndrome Screens
	First-trimester Down Syndrome Screen	Second-trimester Down Syndrome Scree	Second-trimester Down Syndrome Screen	Second-trimester Down Syndrome Screen
Weeks of Pregnancy	11-13+6 weeks	15-20 weeks	15-20 weeks	15-20 weeks
Item	High-level ultrasound (nuchal translucency) and maternal serum test (PAPP-A + β-hCG)	Maternal serum quadruple test (AFP, β-hCG, uE3, and Inhibin A)	Maternal serum triple test (AFP, β-hCG, and uE3)	Maternal serum double test (AFP +β-hCG)
Detection Rate	85%	83%	69-77%	50-60%
Advantages	1.The test can be carried out earlier on during the first trimester and has a high detection rate.	1.The test has a higher detection rate than the traditional maternal serum double test.	Less expensive	Less expensive
	2.One is able to undergo high-level ultrasound early in pregnancy, allowing for earlier observation of the fetus.	2.Probabilities of the fetus having a neural defect and the Edward’s syndrome (Trisomy 18) can be found out at the same time.