What is the next step for a pregnant patient presenting with vaginal bleeding?

For a pregnant patient presenting with vaginal bleeding, the most appropriate next step is to perform an ultrasound. This imaging modality is critical in a case of vaginal bleeding during pregnancy as it can help to determine the viability of the pregnancy, assess for any fetal cardiac activity, evaluate the placental location, and identify any potential ectopic pregnancy or other abnormalities.

Ultrasound provides important information that can guide further management and is essential in the evaluation of both the mother and the fetus in this scenario. It is a non-invasive procedure that can quickly give definitive information regarding the state of pregnancy, which is crucial in making clinical decisions.

While monitoring the fetal heart rate with a nonstress test (NST) can be valuable in certain situations, it is typically not the first step in the acute assessment of vaginal bleeding. Instead, it is more appropriate in cases where the pregnancy is established and there are other indications for fetal monitoring.

A digital vaginal exam and a pelvic exam can provide information about the cervix and help determine if there is active bleeding from the cervix, but they do not provide the comprehensive information that an ultrasound offers regarding the status of the pregnancy. These physical exams can also pose a risk of infection or further complications when there is active vaginal bleeding.