ACOG clinical recommendations support the use of fetal fibronectin testing to help rule out patients with symptoms who are at reduced risk of having a preterm birth, to help avoid unnecessary interventions.
Assessment of risk factors for preterm birth1
The following recommendations relate to risk factors, markers for predicting preterm birth, and clinical considerations:
- There are no current data to support the use of salivary estriol, HUAM, or BV screening as strategies to identify or prevent preterm birth.
- Screening for risk of preterm labor by means other than historic risk factors is not beneficial in the general obstetric population.
- Ultrasonography to determine cervical length, fFN (fetal fibronectin) testing, or a combination of both may be useful in determining women at high risk for preterm labor. However, their clinical usefulness may rest primarily with their negative predictive value given the lack of proven treatment options to prevent preterm birth.
- Fetal fibronectin testing may be useful in women with symptoms of preterm labor to identify those with negative values and a reduced risk of preterm birth, thereby avoiding unnecessary intervention.
Management of preterm labor2
Many factors influence the decision to intervene when women have symptoms of preterm labor, including the probability of progressive labor, gestational age, and the risks of treatment. According to ACOG practice bulletin No. 43, 2003: "Many tests to identify women at risk of preterm birth have been proposed and evaluated; however, only ultrasonography and fetal fibronectin testing have been shown to have benefit."
- There are no clear "first-line" tocolytic drugs to manage preterm labor. Clinical circumstances and physician preferences should dictate treatment.
- Antibiotics do not appear to prolong gestation, and should be reserved for group B streptococcal prophylaxis in patients in whom delivery is imminent.
- Neither maintenance treatment with tocolytic drugs nor repeated acute tocolysis improve perinatal outcome; neither should be used as a general practice.
- Tocolytic drugs may prolong pregnancy for two to seven days, which may allow for administration of steroids to improve fetal lung maturity and the consideration of maternal transport to a tertiary care facility.
- Cervical ultrasound examination and fetal fibronectin testing have good negative predictive value; thus, either approach or both combined may be helpful in determining which patients do not need tocolysis.
- Amniocentesis may be used in women in preterm labor to assess fetal lung maturity and intra-amniotic infection.
- Bed rest, hydration, and pelvic rest do not appear to improve the rate of preterm births, and should not routinely be recommended.
- 1. American College of Obstetricians and Gynecologists. Assessment of risk factors for preterm birth. ACOG Practice Bulletin 31. Washington, DC: ACOG, 2001.
- 2. American College of Obstetricians and Gynecologists. Management of preterm labor. ACOG Practice Bulletin No. 43. Obstet Gynecol. 2003;101:5:1039-47.