Why do we view fetuses using ultrasound and not MRI scans?

Ultrasound is preferred for viewing fetuses because it is safer, more accessible, and provides real-time imaging. It uses sound waves rather than ionizing radiation, making it ideal for monitoring fetal development throughout pregnancy. MRI scans, while providing detailed images, are more expensive, less portable, and take longer, making them less practical for routine fetal assessments. Additionally, MRI may pose risks in certain situations, such as during early pregnancy.