One big advantage 4 has over 3 is the lack of rabbitholes. If you have the Get to Work expansion installed, you can choose to have a baby at a hospital and you can navigate around the hospital just like any normal place. It's kind of funny how they always surgically remove the baby. It's not even a c-section - they literally use the same thing they use for complex surgeries. And the animation shows the nurses accidentally pulling other organs sometimes. It's crazy.