Placenta previa most commonly presents with which symptom in the third trimester?

• A. Painful vaginal bleeding in the third trimester
• B. Painless vaginal bleeding in the third trimester
• C. Severe abdominal pain with fetal distress
• D. No bleeding but contractions

Answer: (B)

Placenta previa presents with painless vaginal bleeding in the third trimester. This happens because the placenta implants low in the uterus near or over the cervix, so bleeding can occur as the uterus grows or with mild irritation without causing painful contractions. The absence of significant pain is a hallmark, even when the bleeding is heavy.

Painful vaginal bleeding in the third trimester points more to placental abruption, where the placenta detaches from the uterine wall and the uterus often becomes tender and firm with cramping or contractions. Severe abdominal pain with fetal distress similarly suggests abruption or another urgent obstetric issue, not placenta previa. No bleeding but contractions would be typical of labor or Braxton Hicks contractions, not placenta previa.

In the field, if a patient in the third trimester has vaginal bleeding that is painless, you should suspect placenta previa, avoid performing a vaginal exam unless you’re sure there isn’t placenta previa, provide airway and circulation support as needed, monitor vitals, and transport for obstetric care promptly.