what are the risk factors that may impact someone having a child with down syndrome?
dr. m.: there are different thoughts on different risk factors, but the main one that’s been shown is advanced maternal age where the mother is over 35. in saying that, the majority of people who are born with down syndrome are born to women less than age 35 just because the majority of babies are being born in that age range. and that’s across cultures, socioeconomic status and race.
how is down syndrome diagnosed in pregnancy?
dr. m.: through screening. in modern medicine, we’re taught to offer screening to every pregnant woman who walks through our door. the first one is the first trimester screening, which uses a combination of blood levels, as well as measurements from an ultrasound to come up with the chance that your baby has down syndrome, or some other genetic abnormality. the blood levels specifically are proteins that are found in the placenta and then the ultrasound is of the baby’s neck [that measures the thickness of the tissue], called a nuchal translucency test. the scores from each of these determine high risk versus low risk.
if that test is missed — because some people aren’t aware that they’re pregnant until later — there’s another test that uses blood levels, looking at particular proteins that are primarily concentrated in the placenta. one thing to be aware of with these is that it’s the risk of your baby having down syndrome — nothing is definitive.