4D ultrasound is an advanced prenatal imaging technology that provides a real-time, three-dimensional view of the developing baby inside the mother’s womb, where the fourth dimension represents live movement over time. Unlike conventional 2D ultrasound, which produces flat black-and-white images, or 3D ultrasound, which offers still images with depth, 4D ultrasound allows parents and healthcare professionals to observe the baby’s natural movements as they happen. These may include facial expressions such as smiling, yawning, blinking, or frowning, as well as body movements like stretching, kicking, sucking a thumb, or grasping with tiny hands. This technology is most commonly performed between 24 and 32 weeks of pregnancy, a period when the baby has developed enough facial fat and muscle tone to create clearer and more detailed images, while still having enough space in the womb to move freely. From a medical perspective, 4D ultrasound can help doctors observe fetal behavior, movements, and certain external structures, which may support the evaluation of facial abnormalities or developmental concerns when clinically indicated. From an emotional and bonding standpoint, it offers parents a unique and memorable experience by allowing them to see their baby’s features and personality before birth, often strengthening emotional attachment and reassurance. The procedure uses the same sound-wave technology as standard ultrasound and is generally considered safe when performed responsibly by trained professionals, following recommended guidelines and avoiding unnecessary prolonged exposure. Overall, 4D ultrasound combines medical insight with an enhanced visual experience, making it a valuable tool for both clinical observation and parental connection during pregnancy.