Aim: Since the two invasive diagnostic procedure, chorionic villus sampling and amniocentesis play important role in prenatal diagnosis, evaluation of their maternal and fetal risks is one of the most important part of genetic counselling.
New developments: There are numerous factors that influence the specific risk of fetal aberrations or chromosomal abnormalities of the actual fetus. Risk factors and different conditions, modifying the procedure-related risk are discussed in the paper together with new chapters of prenatal diagnosis.
Conclusion: The authors underline that individually tailored risk-assessment needs to be established during pre-procedure genetic counselling. This should take into account all the factors having impact on the specific risk in the actual pregnancy. Psychologic factors and recent scientific developments should also be discussed in order to give most information to the parents before they decide about taking any invasive procedure.