This is the current release of the guideline.

This guideline updates a previous version: American College of Obstetricians and Gynecologists (ACOG). Management of preterm labor. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2003 May. 9 p. (ACOG practice bulletin; no. 43). [74 references]

Preterm labor

To present the various methods proposed to manage preterm labor and to review the evidence for the roles of these methods in clinical practice

Note: Identification and management of risk factors for preterm labor are not addressed in this document.

Women in preterm labor

The MEDLINE database, the Cochrane Library, and the American College of Obstetricians and Gynecologists' own internal resources and documents were used to conduct a literature search to locate relevant articles published between: January 1990 - March 2012. The search was restricted to articles published in the English language. Priority was given to articles reporting results of original research, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Guidelines published by organizations or institutions such as the National Institutes of Health and the American College of Obstetricians and Gynecologists were reviewed, and additional studies were located by reviewing bibliographies of identified articles. When reliable research was not available, expert opinions from obstetrician–gynecologists were used.

Not stated

Studies were reviewed and evaluated for quality according to the method outlined by the U.S. Preventive Services Task Force.

I Evidence obtained from at least one properly designed randomized controlled trial

II-1 Evidence obtained from well-designed controlled trials without randomization

II-2 Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group

II-3 Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.

III Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Not stated

Analysis of available evidence was given priority in formulating recommendations. When reliable research was not available, expert opinions from obstetrician-gynecologists were used. See also the "Rating Scheme for the Strength of Recommendations" field regarding Level C recommendations.

Based on the highest level of evidence found in the data, recommendations are provided and graded according to the following categories:

Level A — Recommendations are based on good and consistent scientific evidence.

Level B — Recommendations are based on limited or inconsistent scientific evidence.

Level C — Recommendations are based primarily on consensus and expert opinion.

A formal cost analysis was not performed and published cost analyses were not reviewed.

Practice Bulletins are validated by two internal clinical review panels composed of practicing obstetrician-gynecologists generalists and sub-specialists. The final guidelines are also reviewed and approved by the American College of Obstetricians and Gynecologists (ACOG) Executive Board.

The grades of evidence (I-III) and levels of recommendations (A-C) are defined at the end of the "Major Recommendations" field.

The following recommendations and conclusions are based on good and consistent scientific evidence (Level A):

• A single course of corticosteroids is recommended for pregnant women between 24 weeks of gestation and 34 weeks of gestation who are at risk of preterm delivery within 7 days.
• Accumulated available evidence suggests that magnesium sulfate reduces the severity and risk of cerebral palsy in surviving infants if administered when birth is anticipated before 32 weeks of gestation. Hospitals that elect to use magnesium sulfate for fetal neuroprotection should develop uniform and specific guidelines for their departments regarding inclusion criteria, treatment regimens, concurrent tocolysis, and monitoring in accordance with one of the larger trials.
• The evidence supports the use of first-line tocolytic treatment with beta-adrenergic agonist therapy, calcium channel blockers, or non-steroidal anti-inflammatory drugs (NSAIDs) for short-term prolongation of pregnancy (up to 48 hours) to allow for the administration of antenatal steroids.
• Maintenance therapy with tocolytics is ineffective for preventing preterm birth and improving neonatal outcomes and is not recommended for this purpose.
• Antibiotics should not be used to prolong gestation or improve neonatal outcomes in women with pre-term labor and intact membranes.

The following recommendations and conclusions are based on limited or inconsistent scientific evidence (Level B):

• A single course of repeat antenatal corticosteroids should be considered in women whose prior course of antenatal corticosteroids was administered at least 7 days previously and who remain at risk of preterm birth before 34 weeks of gestation.
• Bed rest and hydration have not been shown to be effective for the prevention of preterm birth and should not be routinely recommended.
• The positive predictive value of a positive fetal fibronectin test result or a short cervix alone is poor and should not be used exclusively to direct management in the setting of acute symptoms.

Definitions:

Grades of Evidence

I Evidence obtained from at least one properly designed randomized controlled trial

II-1 Evidence obtained from well-designed controlled trials without randomization

II-2 Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group

II-3 Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.

III Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Levels of Recommendations

Level A — Recommendations are based on good and consistent scientific evidence.

Level B — Recommendations are based on limited or inconsistent scientific evidence.

Level C — Recommendations are based primarily on consensus and expert opinion.

None provided

The type of supporting evidence is identified and graded for each recommendation (see the "Major Recommendations" field).

Safe and effective management of women with preterm labor

Common Tocolytic Agents

Calcium Channel Blockers

• Maternal side effects: Dizziness, flushing, and hypotension; suppression of heart rate, contractility, and left ventricular systolic pressure when used with magnesium sulfate; and elevation of hepatic transaminases
• Fetal or newborn adverse effects: No known adverse effects

Non-steroidal Anti-inflammatory Drugs (NSAIDs)

• Maternal side effects: Nausea, esophageal reflux, gastritis, and emesis; platelet dysfunction is rarely of clinical significance in patients without underlying bleeding disorder
• Fetal or newborn adverse effects: In utero constriction of ductus arteriosus*, oligohydramnios*, necrotizing enterocolitis in preterm newborns, and patent ductus arteriosus in newborn†

*Greatest risk associated with use for longer than 48 hours

†Data are conflicting regarding this association

Beta-adrenergic Receptor Agonists

• Maternal side effects: Tachycardia, hypotension, tremor, palpitations, shortness of breath, chest discomfort, pulmonary edema, hypokalemia, and hyperglycemia
• Fetal or newborn adverse effects: Fetal tachycardia

Magnesium Sulfate

• Maternal side effects: Causes flushing, diaphoresis, nausea, loss of deep tendon reflexes, respiratory depression, and cardiac arrest; suppresses heart rate, contractility and left ventricular systolic pressure when used with calcium channel blockers; and produces neuromuscular blockade when used with calcium-channel blockers.
• Fetal or newborn adverse effects: Neonatal depression (The use of magnesium sulfate in doses and duration for fetal neuroprotection alone does not appear to be associated with an increased risk of neonatal depression when correlated with cord blood magnesium levels.)

These guidelines should not be construed as dictating an exclusive course of treatment or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to the institution or type of practice.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

American College of Obstetricians and Gynecologists (ACOG)

American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins — Obstetrics

American College of Obstetricians and Gynecologists (ACOG) committees are created or abolished and their overall function defined by the Executive Board. Appointments are made for one year, with the understanding that such appointment may be continued for a total of three years. The majority of committee members are Fellows, but Junior Fellows also are eligible for appointment. Some committees may have representatives from other organizations when this is particularly appropriate to committee activities. The president elect appoints committee members annually.

Not stated

This is the current release of the guideline.

This guideline updates a previous version: American College of Obstetricians and Gynecologists (ACOG). Management of preterm labor. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2003 May. 9 p. (ACOG practice bulletin; no. 43). [74 references]

Electronic copies: None available

Print copies: Available for purchase from the American College of Obstetricians and Gynecologists (ACOG) Distribution Center, PO Box 933104, Atlanta, GA 31193-3104; telephone, 800-762-2264, ext. 192; e-mail: sales@acog.org. The ACOG Bookstore is available online at the ACOG Web site .

The following is available:

• Magnesium sulfate before anticipated preterm birth for neuroprotection. Patient safety checklist. Atlanta (GA): American College of Obstetricians and Gynecologists (ACOG); 2012 Aug. 2 p. Electronic copies: Available in Portable Document Format (PDF) from the American College of Obstetricians and Gynecologists (ACOG) Web site.

In addition, a proposed performance measure is included in the original guideline document.

The following is available:

• Frequently asked questions: Preterm Labor Atlanta (GA): American College of Obstetricians and Gynecologists (ACOG); 2011 May. 3 p. Electronic copies: Available in Portable Document Format (PDF) from the American College of Obstetricians and Gynecologists (ACOG) Web site.

Please note: This patient information is intended to provide health professionals with information to share with their patients to help them better understand their health and their diagnosed disorders. By providing access to this patient information, it is not the intention of NGC to provide specific medical advice for particular patients. Rather we urge patients and their representatives to review this material and then to consult with a licensed health professional for evaluation of treatment options suitable for them as well as for diagnosis and answers to their personal medical questions. This patient information has been derived and prepared from a guideline for health care professionals included on NGC by the authors or publishers of that original guideline. The patient information is not reviewed by NGC to establish whether or not it accurately reflects the original guideline's content.

This summary was completed by ECRI on February 4, 2004. The information was verified by the guideline developer on July 26, 2004. The information was reaffirmed by the guideline developer in 2008 and updated by ECRI Institute on February 9, 2010. This summary was updated by ECRI Institute on March 11, 2011 following the U.S. Food and Drug Administration (FDA) advisory on Terbutaline. This NGC summary was updated by ECRI Institute on January 21, 2013.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.