Final answer:
The first sign that a fallopian ectopic pregnancy had ruptured is severe abdominal pain.
Step-by-step explanation:
The first sign that a fallopian ectopic pregnancy had ruptured is severe abdominal pain. This pain occurs because the rupture causes bleeding in the pelvis, which triggers inflammation and can cause internal scar tissue. Vaginal bleeding may also occur, but severe abdominal pain is typically the most significant symptom. This is a medical emergency and can be characterized by sudden, intense pain in the abdomen, along with other symptoms such as vaginal bleeding, dizziness, and referred shoulder pain due to irritation of the diaphragm.
For example, if a woman experiences sudden, severe pain in her lower abdomen along with other symptoms such as dizziness or shoulder pain, it could be a sign of a ruptured ectopic pregnancy.