Which complication may present with severe abdominal pain but typically without vaginal bleeding?

The correct answer is that ovarian torsion may present with severe abdominal pain but typically without vaginal bleeding. Ovarian torsion occurs when an ovary becomes twisted around the ligaments that support it, leading to a reduction in blood flow. This condition often results in sudden onset of severe, unilateral abdominal or pelvic pain, which can sometimes radiate to the back or thigh.

In contrast, conditions like ruptured ectopic pregnancy, placenta previa, and abruptio placenta typically involve some degree of vaginal bleeding. A ruptured ectopic pregnancy usually presents with sharp abdominal pain and can lead to internal bleeding, which is often accompanied by vaginal spotting or bleeding. Placenta previa, a condition where the placenta partially or wholly covers the cervix, often results in painless vaginal bleeding as the pregnancy advances. Abruptio placenta, characterized by the separation of the placenta from the uterus, typically presents with abdominal pain along with vaginal bleeding as a major symptom. Therefore, when assessing severe abdominal pain without the presence of bleeding, ovarian torsion is the most applicable diagnosis among the choices given.