Perinatal outcomes related to induction of labor: a call for randomized trials.

ll obstetric clinicians know that induction of labor A causes more cesarean deliveries. If you spend time on the labor floor, you can see that women who are induced end up with more cesareans than those who experience spontaneous labor. However, we have been confused and wrong regarding this issue for decades. This is because at any gestational age, the options for a clinician and patient are not induction of labor vs spontaneous labor but induction of labor vs expectant management. Expectant management encompasses having the patient progress into the future in which a wide variety of things could occur. She may go into spontaneous labor, but she may also develop a complication of pregnancy such as preeclampsia, fetal growth restriction, or oligohydramnios. If she progresses to 41 or 42 weeks’ gestation, most clinicians will induce at that point, even without another complication, but now the patient has an increased risk of fetal macrosomia as well. Similarly, it appears that with greater gestational age at term, the risk of uteroplacental insufficiency rises, leading to more cesareans for fetal intolerance of labor. Thus, expectant management at term has a number of associated complications that all may contribute to an increased risk of cesarean. In a randomized trial, one compares induction of labor to expectant management. There are a number of these trials conducted at 41 or 42 weeks’ gestation, and in metaanalyses, induction of labor has been shown to decrease the risk of cesarean delivery compared with expectant management. There are far fewer studies conducted prior to 41 weeks’ gestation, but these, too, have demonstrated a reduction in the risk of cesarean delivery. One randomized trial of a preventive induction of labor was not statistically powered to show a reduction in the cesarean delivery rate but did show a reduction in fetal morbidity as measured by the adverse outcome index.