C-section post abd surgery?

Three years ago, a family member had a misdiagnosised ectopic pregnancy. The docs tried treating it pharmacologically, but it was too late and it failed. After being all night in the ER, docs decided surgery was needed. Were going to do laproscopically, but the tube had ruptured and there was too much blood. The doc did a typical C-section incision.
Now here we are, family member is pregnant. Being told, my need C-section due to abd surgery. Uterus is intact.
Why would a C-section be necessary since it was an abd incision and the uterus was not cut? Is there the possiblity that the abd incision could ruputre during labor and delivery?
Thanks!