Can I take a test to see if my fetus will have down syndrome?

Yes. The diagnostic test for down syndrome is a fetal chromosome analysis or karyotype with fetal cells obtained by either chorionic villus sampling or amniocentesis. Both tests have complication risks. There are less invasive tests using ultrasound and blood tests that can suggest an elevated risk, but they only assess risks and are not diagnostic.
Two testing levels. Ds diagnosis can be suggested on both a simple blood test and a specialized ultrasound. These are considered non- invasive with little or no risk for you are baby. A more definitive result can be obtained by chorionic villus sampling or amniocentesis. These are invasive tests with risks for you both including loss of the pregnancy. Discuss both with your ob.