When does screening for down's syndrome begin?

At 10 weeks...: ...First trimester maternal serum testing and nuchal translucency by fetal ultrasonography begin and can be followed by the maternal serum quad testing for a combined detection rate of 95% with 5%-8% false positives. These non-invasive test results can be validated by chorionic villus sampling (cvs) at about 10 or by amniocentesis at about 15 gestational weeks.

Downs syndrome: Recent reports indicate there is a blood test that can determine downs syndrome very early in the pregnancy. The standard approach has been amniocentesis done between 12 and 16 weeks of the pregnancy. Additional tests include a non invasive echo looking for nuchal folds chorionic villus testing.

First trimester: Screening for Down syndrome can begin as early as 11-14 weeks during the first trimester using a blood test and measurements on an ultrasound. Additional screening tests can be performed in the second trimester (~15-20 weeks) to add specificity to the testing. Together, the tests can detect Down syndrome with greater than a 95% detection rate.

Depends on interest: The NIPP is a non-invasive test that examines fetal cells in mother's blood.While promoted as a paternity test, it can be used as an accurate way to detect chromosome abnormalities like DS as early as 8 weeks into pregnancy. Less accurate screening tests like ultrasound are not invasive but less definite and done later.Amniocentesis done at 16 weeks is definite but invasive. Some mothers don't