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Latent phase of labor

Andrew J Satin, MD, FACOG
Section Editor
Vincenzo Berghella, MD
Deputy Editor
Vanessa A Barss, MD, FACOG


Normal labor refers to the presence of regular uterine contractions that cause progressive dilation and effacement of the cervix and fetal descent. It is viewed in terms of its phases: latent and active; and its stages: first, second, and third.

The latent phase of labor will be reviewed here. Other aspects of labor and labor abnormalities are discussed separately:

(See "Normal and abnormal labor progression".)

(See "Management of normal labor and delivery".)


Latent phase — The initial phase of labor is termed the latent phase. It begins at the point at which the woman perceives regular uterine contractions, usually every three to five minutes for at least an hour, but this is variable. These contractions gradually soften, efface, and begin to dilate the cervix. This simple definition belies a complex process not completely understood by modern science. Women have irregular contractile activity beginning in the midtrimester, and gradual changes in the consistency, position, dilation, and effacement of the cervix occur over the remaining months of the pregnancy [1,2]. This makes accurate assessment of the onset of latent phase difficult since determining exactly when a patient has entered latent phase is primarily based upon the woman's history and the judgment of the attending provider.

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Literature review current through: Nov 2017. | This topic last updated: May 11, 2017.
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