Placenta previa is best described as

• A. Placenta detaches from the uterus causing painful bleeding
• B. Abnormal invasion of placenta into myometrium
• C. Fetal distress due to placental insufficiency
• D. Placenta overlies the cervical os causing painless bleeding

Answer: (D)

Placenta previa happens when the placenta implants in the lower part of the uterus, near or over the cervical opening. Because the placental tissue lies over the cervix, bleeding can occur with minimal uterine contraction, leading to painless vaginal bleeding in the second or third trimester. This painless bleeding pattern is the hallmark that sets placenta previa apart from other placental problems. For example, placental abruption involves the placenta detaching from the uterus and typically causes sudden, painful bleeding with a tender or rigid uterus. Placenta accreta refers to abnormal invasion of the placenta into the myometrium, not its position over the cervix. In practice, confirming previa with ultrasound helps guide safe management, including avoiding digital vaginal exams and planning delivery by cesarean if necessary.