What are the American College of Obstetricians and Gynecologists (ACOG) guidelines for preterm labor?

From the Guidelines

The American College of Obstetricians and Gynecologists (ACOG) recommends that only women with fetuses that would benefit from a 48-hour delay in delivery should receive continuous tocolytic treatment to allow administration of antenatal corticosteroids.

Key Points

• The goal of tocolytic treatment is to prolong pregnancy for 48 hours to allow corticosteroid administration, which improves neonatal outcomes, including respiratory distress syndrome, intracranial hemorrhage, necrotizing enterocolitis, and death 1.
• Standard management of preterm labor includes diagnosis, hydration with intravenous fluids, and use of tocolytic agents such as nifedipine, indomethacin, terbutaline, and magnesium sulfate 1.
• The diagnosis of preterm labor may be complicated in women with skeletal dysplasia due to anatomical differences, and the standard management may need to be modified 1.
• ACOG provides guidance on obstetric interventions for threatened and imminent periviable birth, including recommendations on antenatal corticosteroids, tocolysis, and magnesium sulfate for neuroprotection 1.
• The approach to antenatal and postdelivery care may differ depending on parental preferences regarding resuscitation, and a stepwise approach concordant with neonatal circumstances and condition is appropriate 1.

Tocolytic Agents

• The most commonly used tocolytics in the United States are:
  • Nifedipine (calcium channel blocker)
  • Indomethacin (nonsteroidal anti-inflammatory drug)
  • Terbutaline (beta-adrenergic receptor agonist)
  • Magnesium sulfate
• Many obstetricians have their preferred regimen, as the literature does not strongly favor one over the others 1.

Special Considerations

• Women with skeletal dysplasia may require advanced planning for general and regional anesthesia due to anatomical differences that increase the risk of complications 1.
• The volume of distribution of fluids is proportionate to the patient's stature, and adjustments in infusion volume and rate should be made accordingly to avoid fluid overload 1.

From the Research

American College of Obstetricians and Gynecologists (ACOG) Guidelines for Preterm Labor

• The ACOG guidelines for preterm labor include a multipronged pharmacologic approach targeting utilization of reproductive hormones for continuation of pregnancy, advancement of fetal lung maturity, and the decrease of uterine contractility (tocolysis) 2.
• The guidelines recommend the use of tocolytic agents, corticosteroids, and antibiotics for the management of preterm labor 3.
• The ACOG suggests the use of cervical cerclage in singleton pregnancies with 1 or more previous second trimester miscarriages related to painless cervical dilation or prior cerclage due to painless cervical dilation in the second trimester 4.
• The guidelines emphasize the importance of treating preterm labor up to 34 weeks of gestation, to delay delivery for 48 hours, for the administration of antenatal corticosteroids, magnesium sulfate, and in utero transfer to higher care facility 5.
• The ACOG highlights the significance of screening for preterm labor by transvaginal ultrasound (TVUS) cervical length measurement between 16 and 24 weeks of gestation and suggests the use of either vaginal progesterone or cervical cerclage for the prevention of preterm labor, based on specific indications 5.

Diagnosis and Management of Preterm Labor

• The diagnosis of preterm labor is based on clinical criteria, physical examination, measurement of cervical length (CL) with transvaginal ultrasound (TVUS), and use of biomarkers 5.
• The management of preterm labor includes the use of tocolytic agents, corticosteroids, and antibiotics, as well as the administration of antenatal corticosteroids, magnesium sulfate, and in utero transfer to higher care facility 3, 5.
• The guidelines recommend against routine cesarean delivery in case of preterm labor 5.

Prevention of Preterm Labor

• The ACOG suggests the use of either vaginal progesterone or cervical cerclage for the prevention of preterm labor, based on specific indications 4, 5.
• The guidelines highlight the significance of screening for preterm labor by TVUS CL measurement between 16 and 24 weeks of gestation 5.
• Cervical pessary is not recommended as a preventive measure for preterm labor 5.