Which condition presents with painless vaginal bleeding in the third trimester due to placental implantation over the cervical opening?

• A. Placenta previa
• B. Abruptio placentae
• C. Ectopic pregnancy
• D. Uterine rupture

Answer: (A)

Placenta previa happens when the placenta implants in the lower part of the uterus, covering or near the cervical opening. Because the placental vessels are near the cervix, changes in the cervix or progression of labor can cause bleeding without triggering strong uterine contractions, so the bleeding tends to be painless. This typically presents in the third trimester as painless vaginal bleeding with a uterus that is not tender.

In contrast, conditions like abruptio placentae cause painful bleeding with abdominal tenderness or a rigid uterus, often with uterine contractions and fetal distress; ectopic pregnancy presents early in pregnancy with abdominal pain and vaginal bleeding; and uterine rupture typically produces severe pain and signs of maternal or fetal compromise during labor, especially with prior uterine surgery. So the painless third-trimester bleeding due to placental placement over the cervical opening points to placenta previa.