The authors report no financial relationships relevant to this article.
In recent years, prenatal screening and testing have begun to shift from the second trimester to the first. Ultrasonographic evaluation—a large component of fetal testing—is also applied earlier in gestation to provide information to clinicians and patients about the integrity of the pregnancy. The shifting of the classic, “gold standard” anatomy scan to the first trimester was made possible by high-frequency transvaginal transducers and by greater understanding of the early signs of fetal pathology.