OBSTETRIC ULTRASOUND IN THE FIRST TRIMESTER: REVIEW OF RECOMMENDATIONS AND LIMITATIONS

Abstract

First-trimester obstetric ultrasound plays a fundamental role in the initial assessment of pregnancy, being a safe, accessible, and clinically relevant method. This study aims to review the main recommendations and limitations of this examination based on current guidelines and scientific literature. This is an integrative review conducted using articles selected from PubMed and SciELO databases, with descriptors related to obstetric ultrasound and the first trimester of pregnancy. First-trimester ultrasound allows confirmation of pregnancy viability, accurate gestational age estimation, diagnosis of ectopic pregnancy, and early risk assessment, such as aneuploidy screening through nuchal translucency. However, it has limitations related to operator dependence, technical variability, and lower sensitivity for some early structural malformations. It is concluded that, despite its limitations, first-trimester ultrasound is essential in obstetric practice and should be interpreted alongside clinical data and complementary tests.