Article Sections

Introduction

Labor is defined by regular and painful uterine contractions that lead to cervical dilation and effacement.  The primary goal of labor management is to achieve a vaginal delivery of a live neonate while minimizing maternal risk.  The 3 components of labor that determine the success of a vaginal delivery include: passageway, passenger, and power.

The primary focus of this article is normal labor.  A separate review article will discuss abnormalities within labor and delivery.

Passageway

This component refers to the maternal bony pelvis and the soft structures of the birth canal, including the cervix, vagina, and vaginal introitus.

The maternal pelvis is divided into imaginary planes that hold obstetric significance: the plane of the pelvic inlet, the plane of the midpelvis, and the plane of the pelvic outlet.

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