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 the early gestational sac and prenatal diagnosis have helped both drive and meet these expectations. We discuss the use, advantages, potential risks and complications of invasive prenatal diagnostic procedures in early pregnancy. All invasive procedures should be performed under continuous ultrasound guidance by experienced operators. Within this context, mid-trimester amniocentesis remains the safest invasive procedure. Chorionic villus sampling (CVS) and early amniocentesis (EA) are associated with a higher risk of subsequent pregnancy loss. There is also a 10-fold increase in the risk of mosaicism with CVS compared to amniocentesis. Both CVS and EA can induce fetal structural defects and should be abandoned as routine invasive tests. Patient counselling should include an evaluation of the risk associated with each individual procedure but also the operator's personal complication rate.