Cesarean delivery rate of women delivering at term ( 37 weeks ' gestation ) was evaluated by 2 complementary approaches : ( 1 ) IOL vs spontaneous labor : women who were induced at each GA compared with those who spontaneously labored at the same GA and ( 2 ) IOL vs expectant management : women who delivered after IOL at each GA compared with those who delivered after spontaneous labor at the same GA or subsequently after spontaneous or induced labor ( outcome at each week compared with expectant management at that week ) .