TY - CHAP M1 - Book, Section TI - First Trimester Pregnancy A1 - Ball, Christian L. A1 - Hess, Jamie M. A1 - Reardon, Robert F. A2 - Ma, O. John A2 - Mateer, James R. A2 - Reardon, Robert F. A2 - Byars, Donald V. A2 - Knapp, Barry J. A2 - Laudenbach, Andrew P. PY - 2021 T2 - Ma and Mateer's Emergency Ultrasound, 4e AB - Ultrasound is the primary imaging modality used in pregnancy, and it is critical for assessing patients in their first trimester who present with vaginal bleeding or abdominal pain.1−3 Point-of-care ultrasound (POCUS) in the first trimester is primarily used to identify an intrauterine pregnancy, which usually excludes the diagnosis of ectopic pregnancy.4 It can also help identify threatened abortion or embryonic demise. Secondary objectives are to detect extrauterine signs of an ectopic pregnancy, estimate the viability of an intrauterine pregnancy, clarify gestational age, and characterize other causes of pelvic pain and vaginal bleeding. In addition, sonographic detection of free fluid outside of the pelvis can help emergency and acute care providers expedite the care of a patient with a ruptured ectopic pregnancy.5 POCUS is not intended to define the entire spectrum of pelvic pathology in early pregnancy. A follow-up comprehensive pelvic ultrasound examination may be indicated after the initial focused POCUS examination, the timing of which is dictated by the clinical scenario. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1175882224 ER -