What is ultrasound primarily used for in pregnancy?

Ultrasound is primarily utilized in pregnancy for a variety of diagnostic and monitoring purposes, with a significant focus on visualizing the developing fetus and related structures. While the answer provided identifies diagnosing causes of vaginal bleeding as a primary use, the most accurate application of ultrasound is assessing placental position, which is critical for ensuring maternal and fetal safety.

Ultrasound allows healthcare providers to visualize the placenta's location, helping to identify conditions such as placenta previa, where the placenta covers the cervix, thus causing complications during delivery. This information is essential for planning appropriate management throughout the pregnancy and for determining the safest delivery method.

Moreover, while healthcare providers do use ultrasound to monitor fetal heart rate and evaluate aspects of maternal health, those functions may be secondary. Diagnosing causes of vaginal bleeding is occasionally part of the ultrasound's role, but the primary purpose leans more towards visualizing fetal and placental anatomy, making the assessment of placental position the correct focus in this context.