Labor Signs

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Medical Author:

Jane K Witman, MD

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Labor Signs Overview
• Labor Signs Causes
• Labor Signs Symptoms
• Preparing for Labor
• When to Call a Health Care Professional
• Synonyms and Keywords
• Authors and Editors
• Viewer Comments: Labor Signs - Pain
• Viewer Comments: Labor Signs - At 35 To 39 Weeks

Labor Signs Overview

The onset of labor is the most anticipated event of pregnancy. Many pregnant women fear they will miss the early signs of labor and be unprepared for the delivery of their child. Fortunately, the body provides several clues that the onset of labor is approaching. There are also signs of pre-labor that indicate that the body is preparing for delivery in the weeks to come. Since a normal gestation is 40 weeks, signs of pre-labor may be apparent at 38 or 39 weeks' gestation. In most cases, labor begins between 37 and 42 weeks after the last menstrual period. Of course, labor may also begin prematurely in some cases. Although gestational age can predict to a certain extent when the signs of labor and pre-labor will develop, there is no proven way to predict precisely when labor will begin.

Labor Signs Causes

No one knows exactly how labor starts. Some researchers think hormonal changes in the fetus cause the placenta to produce increased levels of a substance known as corticotropin-releasing hormone. This changes the balance of the mother's hormones, which have kept the uterus in a relaxed state. Once the process is triggered, the cervix begins to soften and thin. In most cases, contractions signaling labor begin.