Screening for chromosomal abnormalities including Downs Syndrome, Trisomy 18 & 13 are completely optional. If you choose to pursue screening you have many different options.

The first option is Chorionic Villus Sampling (CVS). This is done between 10-13 weeks and involves removing cells from the placenta. The second option is an amniocentesis done between 16-18 weeks which involves sampling the amniotic fluid around the baby. These are both considered invasive tests and carry a small risk of miscarriage (1/200).

Noninvasive testing includes the Quad Screen which measures hormones in the maternal bloodstream drawn between 15-21 weeks. The accuracy of this blood test is 81%. Another noninvasive option is a First Trimester Screen. This involves an ultrasound done by the perinatologist in town between 11-13 weeks and blood testing. The ultrasound measures nuchal translucency and a blood test measures bHCG and PAPPA in the mother’s blood. The detection rate for Down’s Syndrome with the First Trimester Screen is 90%. Both the First Trimester Screen and the Quad Screen have a 5% false positive rate.