Normal Labor: Physiology, Evaluation, and Management

Labor is the normal physiologic process through which the fetus, placenta, and other products of conception are delivered from the uterus through the vagina. Regular uterine contractions cause progressive cervical dilation and effacement, ultimately leading to expulsion of the uterine contents. Human labor is divided into 3 stages. The 1st stage commences with the onset of labor and ends when the cervix is fully dilated to 10 cm. The 2nd stage starts with complete cervical dilation and concludes with fetal delivery. The 3rd stage begins immediately after fetal delivery and ends with placental delivery. Accurate identification of the parturient's stage of labor, appropriate support at each stage, and continuous monitoring help the healthcare team minimize unnecessary interventions and optimize maternal and fetal outcomes, including the parturient's perception of the birth experience. This activity discusses the physiology of normal labor and the recommended evaluation and management by the interprofessional team during spontaneous labor in healthy parturients with uncomplicated singleton pregnancies. More intensive care is often required for parturients with medical comorbidities or maternal or fetal complications, which is covered elsewhere.