First-trimester sonographic findings associated with poor intrauterine outcome

First-trimester sonography is an essential tool in the assessment of the viability of the early pregnancy. Familiarity with prognostic indicators, such as abnormalities of the gestational sac, yolk sac, and embryonic heart rate, allow the sonologist to appropriately caution patients or allay fears in the face of possible pregnancy loss. In addition, first-trimester sonographic evaluation can detect early fetal malformations and placental abnormalities (molar pregnancy or abruption). This article reviews the role of sonography in the first trimester, focusing on its role in dating pregnancies, assessing early fetal viability, and evaluating possible malformations. The discussion also includes assessment of first-trimester patients with multiple gestations and pregnancies conceived with assisted reproductive techniques.