A client at 28-weeks gestation arrives at the labor and delivery unit with a complaint of bright red, painless vaginal bleeding. For which diagnostic procedure should the nurse prepare the client?

• A. Contraction stress test.
• B. Internal fetal monitoring.
• C. Abdominal ultrasound.
• D. Lecithin-sphingomyelin ratio.

Answer: (C)

Painless bright-red bleeding in the midtrimester most often points to placenta previa until proven otherwise. The best next step to confirm this and guide management is an abdominal ultrasound, because it noninvasively shows the placenta’s location and its relation to the cervix. Knowing whether the placenta covers the internal os determines whether vaginal delivery is safe and how to monitor the patient for potential bleeding.

Contraction stress testing is used later to assess fetal tolerance to labor, not to locate the placenta. Internal fetal monitoring is invasive and unnecessary for diagnosing placenta previa. The lecithin-sphingomyelin ratio assesses fetal lung maturity, which isn’t relevant to evaluating bleeding sources or placental position in this scenario.