Prenatal screening tests are generally considered safe for both mother and baby and can be performed for all pregnant individuals who opt for them. However, invasive prenatal diagnostic procedures, which involve entering the sterile intrauterine environment with a needle, carry a small risk of miscarriage. For amniocentesis and chorionic villus sampling (CVS), this risk is approximately 1 in 200 to 1 in 400. For cord blood sampling (cordocentesis), the risk is around 2 in 100.