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Intrapartum fetal heart rate assessment

David A Miller, MD
Section Editor
Vincenzo Berghella, MD
Deputy Editor
Vanessa A Barss, MD, FACOG


Normal human labor is characterized by regular uterine contractions and repeated episodes of transient interruption of fetal oxygenation. Most fetuses tolerate this process well, but some do not. The fetal heart rate (FHR) pattern helps to distinguish the former from the latter as it is an indirect marker of fetal cardiac and central nervous system responses to changes in blood pressure, blood gases, and acid-base status. (See "Nonstress test and contraction stress test", section on 'Physiologic basis of fetal heart rate changes'.)

The rationale for intrapartum FHR monitoring is that identification of FHR changes potentially associated with inadequate fetal oxygenation may enable timely intervention to reduce the likelihood of hypoxic injury or death. Although virtually all obstetric societies advise monitoring the FHR during labor, the benefit of this intervention has not been clearly demonstrated and this position is largely based upon expert opinion and medicolegal precedent.

The procedure for intrapartum FHR monitoring, physiology behind FHR accelerations and decelerations, classification of FHR tracings, and use of ancillary tests to evaluate the fetus will be discussed here. Intrapartum management of category I, II, and III FHR tracing is reviewed separately. (See "Management of intrapartum category I, II, and III fetal heart rate tracings".)Antepartum FHR monitoring (nonstress test, contraction stress test) is also reviewed separately. (See "Nonstress test and contraction stress test".)


Although some evidence suggests that intrapartum fetal monitoring is associated with a reduction in intrapartum death [1], a reduction in long-term neurologic impairment has not been proven. All available data are derived from trials comparing continuous electronic monitoring with intermittent auscultation. There are no randomized trials of intrapartum fetal monitoring versus no intrapartum fetal monitoring.

For both low- and high-risk pregnancies, continuous electronic FHR monitoring is not clearly superior to intermittent auscultation with respect to preventing death or poor long-term neurologic outcome, and has a high false-positive rate [2-4]. A 2017 systematic review that compared continuous electronic FHR monitoring with intermittent auscultation (13 randomized trials, >37,000 low- and high-risk pregnancies) reported the following major findings [4]:

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Literature review current through: Nov 2017. | This topic last updated: Dec 01, 2017.
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