What invasive procedure to use in early pregnancy?

As scientific knowledge and medicine advance so do the expectations of the general public. Advances in molecular biology, ultrasonography, access to t he early gestational sac and prenatal diagnosis have helped both drive and meet these expectations. We discuss the use, advantages, potential risks an d complications of invasive prenatal diagnostic procedures in early pregnan cy. All invasive procedures should be performed under continuous ultrasound guidance by experienced operators. Within this context, mid-trimester amni ocentesis remains the safest invasive procedure. Chorionic villus sampling (CVS) and early amniocentesis (EA) are associated with a higher risk of sub sequent pregnancy loss. There is also a 10-fold increase in the risk of mos aicism with CVS compared to amniocentesis. Both CVS and EA can induce fetal structural defects and should be abandoned as routine invasive tests. Pati ent counselling should include an evaluation of the risk associated with ea ch individual procedure but also the operator's personal complication rate.