OC23.07: A longitudinal study of three‐dimensional fetal anatomy imaging in the first and early second trimester

Abstract

Objectives: Three-dimensional (3D) ultrasound (US) is not used routinely in clinical practice alongside two-dimensional (2D) imaging to assess fetal anatomy. Furthermore, the feasibility of assessing fetal anatomy in the first trimester using 3DUS is unknown. We aim to assess the visualisation rates of normal fetal anatomical structures using 3D ultrasound with novel rendering techniques from 8 to 16 weeks of gestation. Methods: Weekly US examinations were performed on a longitudinal set of 14 consecutively recruited patients from 8 to 16 weeks of gestation. Following a 2D screening US, 3D volumes were acquired and interrogated with Crystal Vue and Realistic VueTM software (Samsung WS80A Elite). A total of 104 scans were performed and the visualisation of anatomical structures in 3D, in accordance with the Fetal Anomaly Screening Programme guidelines, was assessed by one operator. Results: 3D ultrasound enables visualisation of 55% of all fetal anatomical structures (excluding fetal heart) assessed routinely at the 20-week anomaly ultrasound by 10 weeks of gestation, which increases to 91% at 14 weeks gestation. Over 70% of all fetal structures, excluding long bones, could be visualised between 11 to 13 weeks of gestation in 3D. Conclusions: This study confirms the feasibility of 3DUS to visualise fetal anatomy in the first trimester and in particular, at 11 to 13 weeks of gestation when the routine dating scan usually occurs. 3DUS may aid detection and diagnosis of fetal anomalies in a more reliable and reproducible manner well before the anomaly scan. Making the diagnosis of fetal anomaly early in pregnancy using technologies which have the potential to be used in routine practice, and not just by experts, will have a great impact on patient care.