What does a “screen positive” or “abnormal” First Trimester Screen result mean?
A screen positive result does not mean that there is a problem; just that the chance of Down syndrome or Trisomy 18 is higher and there is a need to look more closely at the pregnancy. In most cases, the baby will not have Down syndrome or Trisomy 18. The next step is to visit with a perinatologist who may suggest further testing to help determine whether or not there is actually a problem. A perinatologist will offer you an amniocentesis or chorionic villus sampling (CVS) as a way to test the baby’s chromosomes. In an amniocentesis, the doctor inserts a thin needle through the abdominal wall and into the uterus to withdraw a few teaspoons of amniotic fluid (the fluid surrounding the baby). The baby’s cells in this fluid are tested for Down syndrome and other chromosome abnormalities. Amniocentesis is more than 99% accurate in diagnosing, or more likely, ruling out a chromosome problem. Another option is chorionic villus sampling (CVS), which is done by removing a small sample of the p
