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Diagnosis of preterm labor and overview of preterm birth

Charles J Lockwood, MD, MHCM
Section Editor
Susan M Ramin, MD
Deputy Editor
Vanessa A Barss, MD, FACOG


Identifying women with preterm contractions who will actually deliver preterm is an inexact process, even though preterm labor is one of the most common reasons for hospitalization of pregnant women. Accurate identification of women truly in preterm labor allows appropriate application of interventions that can improve neonatal outcome: antenatal corticosteroid therapy, group B streptococcal infection prophylaxis, magnesium sulfate for neuroprotection, and transfer to a facility with an appropriate level nursery (if necessary). On the other hand, accurate triage of women not actually in preterm labor can avoid performance of unnecessary interventions and associated costs for the 20 to 50 percent of patients with suspected preterm labor who will go on to deliver at term without tocolytic therapy [1].

This topic will describe our approach to the diagnostic evaluation of women who present with possible preterm labor and provide an overview of issues related to preterm birth. Treatment of preterm labor is discussed separately. (See "Inhibition of acute preterm labor".)


Pathogenesis — The pathophysiology of preterm labor involves four primary pathogenic processes that result in a final common pathway ending in spontaneous preterm labor and delivery:

Activation of the maternal or fetal hypothalamic-pituitary-adrenal axis associated with either maternal anxiety and depression or fetal stress



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Literature review current through: Apr 2017. | This topic last updated: Mar 17, 2017.
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