The risk from CVS is slightly higher than the risk from amniocentesis, although some parents feel that it is worth the extra risk to be able to make decisions earlier in the pregnancy should the results indicate the baby has a health problem. There is a risk of miscarriage that is slightly higher than 1 in 300. This might result in your making decisions about pregnancy termination that you would not have made if you had better information.
Some women have vaginal bleeding after the procedure.
Infection is an uncommon risk.