The Quadruple test only uses second trimester markers, and is performed at around 15 or 16 weeks of pregnancy (but between 14 and 22 weeks is possible) when a blood sample is obtained.
This page explains: A sample of your blood is taken at around 15 or 16 weeks of pregnancy (between 14 and 22 weeks is acceptable).
The Antenatal Screening Service has produced two information leaflets for the Quadruple test and Quadruple plus NT test.
The Questions and Answers leaflets are designed for women considering the test and contain the basic information about the screening test and the results.
The four markers are: In pregnancies with Down's syndrome, AFP and u E3 levels tend to be low and h CG and inhibin levels tend to be raised.
The level of AFP is also used to determine if there is an increased risk of spina bifida or anencephaly.
If the risk of having a term pregnancy affected with Down's syndrome is 1 in 150 or higher the result will be screen-positive and you will be offered an amniocentesis.
If the risk is lower than 1 in 150 the result will be screen-negative and an amniocentesis will not be recommended.
Yes, the Quadruple test also identifies pregnancies at a high risk of Edwards’ syndrome (trisomy 18).
The risk of Edwards’ syndrome can be identified using AFP, u E3 and h CG.
Prenatal testing consists of prenatal screening and prenatal diagnosis, which are aspects of prenatal care that focus on detecting problems with the pregnancy as early as possible.
These may be anatomic and physiologic problems with the health of the zygote, embryo, or fetus, either before gestation even starts (as in preimplantation genetic diagnosis) or as early in gestation as practicable.
The sample should be returned in the envelope provided using the Royal Mail Special Delivery Service.