When I was in college I had a short friendship with a woman who'd recently had a daughter. My friend was a very slight person with fairly small hips, but the birthing process had taken her around two hours and one really large squeeze, which broke most of her capillaries.
As she described it, the trick to avoiding a multi-hour ordeal was fairly simple: At the point when things seemed unbearable, she simply told herself "the only way out is through." And then she just squeezed, refusing to let up until it was over.