A Menu of Change

Assessment of Fetal Well-Being

The guidelines and practice standards published by maternity care professional associations in the United States indicate that intermittent auscultation (IA) is as effective as continuous electronic fetal heart rate monitoring (EFM) to assess fetal well-being in women who are at term and who have no obstetric or medical risk factors that increase the risk for fetal acidemia during labor.1-3 In randomized controlled trials and subsequent meta-analyses, the use of EFM increased rates of cesarean and operative vaginal birth without lowering the rates of cerebral palsy or perinatal mortality or improving Apgar scores.4

Click to link to Toolbox Resources

Although EFM performs well in identifying the fetus who does not have acute acidemia, EFM performs poorly in identifying the fetus with acute acidemia because it has a high false positive rate. Variant fetal heart rate patterns are common, but clinically significant metabolic acidemia in the fetus is rare.5 Despite these limitations and the availability of IA as a viable, less invasive alternative, EFM is the predominant means of monitoring fetal well-being during labor in the United States. In a recent national survey, 80% of women reported the use of EFM throughout all or most of their labors.6

Association of Monitoring with Vaginal Birth Rates

The use of IA may improve vaginal birth rates through several mechanisms. IA can be used successfully to identify the most common fetal heart rate patterns associated with fetal acidemia without the false positive results associated with EFM.1 In addition, the use of IA facilitates spontaneous labor because it allows freedom of movement and upright positions that are associated with a lower risk of cesarean birth than recumbent positions.7 Finally, IA requires continuous one-to-one labor support, which also has an independent effect of improving labor outcomes and reducing the risk of cesarean.8

Birth site policies that define eligibility for IA may vary according to local context and site capabilities. IA is appropriate for women who are at term with a singleton fetus in a cephalic presentation and who enter labor with no obstetric or medical conditions that increase the risk developing fetal acidemia during labor. The following exclusion factors are included in many practice policies:

Maternal contraindications

  • Pregnancy complications such as gestational diabetes requiring medication, more than 42 weeks gestation, oligohydramnios, preeclampsia, RH isoimmunization

  • Variant fetal conditions such as multiple gestation, noncephalic presentation

  • Preexisting chronic disease such as autoimmune disorders, cardiac disease, coagulopathies, diabetes, hypertension, renal disease, sickle cell disorder

  • Prior cesarean delivery or other uterine surgery

  • Placental abnormalities such as placenta previa or chronic placental abruption

  • Current substance use

  • Inability to monitor with IA (e.g., obesity, polyhydramnios)

Fetal contraindications

  • Intrauterine growth restriction

  • Major morphologic anomalies

  • In utero infection

  • Bradycardia, tachycardia, recurrent decelerations, irregular FHR rhythm

Intrapartum contraindications

  • Abnormal vaginal bleeding not considered normal bloody show

  • Meconium

  • Chorioamnionitis

  • Epidural anesthesia

  • Pitocin induction/augmentation



Click to view additional resources available in the Assessment of Fetal Well-Being Resource Toolbox, or search our resource library by clicking here.


References

  1. American College of Nurse-Midwives. Intermittent auscultation for intrapartum fetal heart rate surveillance. J Midwifery Womens Health. 2007;52:314-319.

  2. American College of Obstetricians and Gynecologists. Management of intrapartum fetal heart rate tracings: practice bulletin no. 116. Obstet Gynecol. 2010;116:1232–1240.

  3. Association of Women’s Health, Obstetric and Neonatal Nurses. Fetal Heart Monitoring Principles & Practices. 4th ed. Philadelphia. PA: Lippincott; 2009.

  4. Alfirevic Z, Devane D, Gyte GM. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev. 2013;5:CD006066.

  5. Larma JD, Silva AM, Holcroft CJ, Thompson RE, Donohue PK, Graham EM. Intrapartum electronic fetal heart rate monitoring and the identification of metabolic acidosis and hypoxic-ischemic encephalopathy. Am J Obstet Gynecol. 2007;197:301.e1-301.e8.

  6. DeClercq ER, Sakala C, Corry MC, Applebaum S, Herrlich A. Listening to Mothers III: Pregnancy and Birth. New York: Childbirth Connection; 2013.

  7. Lawrence A, Lewis L, Hofmeyr GJ, Styles C. Maternal positions and mobility during first stage labour. Cochrane Database Syst Rev. 2013;10:CD003934.

  8. Hodnett ED, Gates S, Hofmeyr GJ, Sakala C. Continuous support for women during childbirth. Cochrane Database Syst Rev. 2013;7:CD003766.

Credit: Carolyn Spranger Photography



 

© American College of Nurse-Midwives | 8403 Colesville Road, Suite 1550, Silver Spring, MD 20910-6374 | www.midwife.org

space