Invasive Procedures in the First Trimester

Over the past few decades there have been dramatic advances in both ultrasound and genetic laboratory technologies. The combination of these, not either one by itself, has led to an explosion of capabilities to diagnose fetal status earlier and earlier in pregnancy. The major shift in screening from second trimester ultrasounds and multiple marker biochemical screening of the 1990s to first-trimester nuchal translucency, biochemical, and now cell-free DNA screening, has skyrocketed the need for first-trimester definitive diagnostic techniques. In experienced hands chorionic villus sampling (CVS) is as safe (or safer) than amniocentesis, generates far more specimen volume for the lab, and allows couples’ privacy in their reproductive decisions. Early amniocenteses have come and gone. Preimplantation genetic diagnosis (PGD) is an excellent screen in high risk situations, and fetal reduction, particularly when combined with CVS, maximizes the outcomes of multifetal gestations, as well as sometimes allowing couples secondary choices, such as gender preference.