The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) has developed practice guidelines for the performance of third-trimester obstetric ultrasound scans. These guidelines aim to provide healthcare practitioners with a consensus-based approach to diagnostic imaging, reflecting the best practices at the time of issuance. The guidelines cover various aspects of the third-trimester ultrasound, including placental location, fetal presentation, fetal biometry, fetal anomalies, amniotic fluid volume, and Doppler findings. They also address the timing of the scan, typically between 32 and 36 weeks of gestation, and the specific indications for the scan, such as suspected vasa previa or low-lying placenta. The guidelines emphasize the importance of assessing fetal viability, presentation, anatomy, and growth, as well as placental location and fetoplacental Doppler. Additionally, they discuss the detection of fetal anomalies, small-for-gestational age (SGA) and large-for-gestational age (LGA) conditions, and the management of perinatal complications. The guidelines also highlight the role of ultrasound in identifying and managing conditions like placenta previa, placenta accreta spectrum, vasa previa, and breech presentation. Overall, the guidelines aim to improve the accuracy and efficiency of third-trimester ultrasound scans to enhance perinatal and maternal outcomes.The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) has developed practice guidelines for the performance of third-trimester obstetric ultrasound scans. These guidelines aim to provide healthcare practitioners with a consensus-based approach to diagnostic imaging, reflecting the best practices at the time of issuance. The guidelines cover various aspects of the third-trimester ultrasound, including placental location, fetal presentation, fetal biometry, fetal anomalies, amniotic fluid volume, and Doppler findings. They also address the timing of the scan, typically between 32 and 36 weeks of gestation, and the specific indications for the scan, such as suspected vasa previa or low-lying placenta. The guidelines emphasize the importance of assessing fetal viability, presentation, anatomy, and growth, as well as placental location and fetoplacental Doppler. Additionally, they discuss the detection of fetal anomalies, small-for-gestational age (SGA) and large-for-gestational age (LGA) conditions, and the management of perinatal complications. The guidelines also highlight the role of ultrasound in identifying and managing conditions like placenta previa, placenta accreta spectrum, vasa previa, and breech presentation. Overall, the guidelines aim to improve the accuracy and efficiency of third-trimester ultrasound scans to enhance perinatal and maternal outcomes.