percent trisomy 16 was found on CVS. Does this mean my baby will be abnormal?
Not necessarily. Although full trisomy 16 is incompatible with life and is a relatively common cause of first trimester spontaneous abortion, CVS (chorionic villous sample) can confirm only cells present in the placenta and not the baby. It is very unlikely that a pregnancy would survive to the time of CVS (-12 weeks gestation) if there were full trisomy 16. It is currently believed that in most cases showing 100 percent (or less) trisomy 16 in a CVS, the baby will have only or predominantly normal diploid cells, a situation often referred to as ‘confined placental mosaicism’. However, there are increased risks associated with such pregnancies (see below) and it is important to follow-up such findings with amniocentesis, ultrasound, and careful monitoring of maternal health.
