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Fetal distress

Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find one of our health articles more useful.

Synonym: fetal compromise; non-reassuring fetal heart rate trace

Fetal distress refers to the compromise of the fetus due to inadequate oxygen or nutrient supply. This can occur due to maternal, fetal or placental factors. At its most severe it may lead to neonatal brain injury or stillbirth. Its presence may be suspected due to various factors but all have a high false positive rate.

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The main cause of antepartum fetal distress is uteroplacental insufficiency.

Factors within labour are complex but processes such as uteroplacental vascular disease, reduced uterine perfusion, intrauterine sepsis, reduced fetal reserves and cord compression can be involved alone or in combination. Gestational and antepartum factors can modify the fetal response to them.

Reduced liquor volume, maternal hypovolaemia and fetal growth restriction are known associations.

Editor's note

Dr Sarah Jarvis, 12th April 2021

The National Institute for Health and Care Excellence (NICE) has issued new guidance on caesarean birth1. There are no new or updated recommendations which are relevant to fetal distress.


The overall risk of prompt caesarean delivery needed for fetal concern was shown to be 3.1% in an unselected population2. The risk exceeded 20% in patients with severe pre-eclampsia, post-term or fetal growth-restricted fetuses with abnormal Doppler studies and also in women with moderate/severe asthma or severe hypothyroidism.

The vast majority of cases of cerebral palsy in otherwise normal-term infants are not associated with intrapartum hypoxia-ischaemia3.

Risk factors

Includes women with a history of:

Maternal age over 35 years, and particularly over 40, is an independent risk factor for uteroplacental insufficiency, fetal distress and stillbirth; the highest risk is in older women who are also nulliparous4.

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See also the separate Intrapartum Fetal Monitoring article.

Fetal distress presents in varied ways and to differing degrees. It may be suspected by the following, which may also be used for further evaluation of suspected fetal distress:

  • Clinical suspicion when decreased fetal movements are felt by the mother or there is a slowing or stopping of the growth of serial symphysis fundal height.

  • Abnormal sonographic biometric parameters when IUGR or macrosomia is suspected.

  • Doppler ultrasound is particularly valuable when performed up to 34 weeks of gestation:

    • Umbilical artery Doppler may detect changes that reflect increasing placental vascular resistance.

    • Fetal arterial Doppler of, for example, the middle cerebral artery, may detect reduced resistance which has developed to maintain blood flow to the fetal brain when placental function is impaired.

    • Fetal venous Doppler may detect changes indicative of impaired cardiac function and fetal acidosis.

  • Cardiotocography (CTG) shows the fetal heart rate response to fetal movement and to maternal contractions. The trace it produces may be described as reassuring, non-reassuring or abnormal:

    • Antenatal CTG:

      • A normal fetal heart rate accelerates with fetal movement and is described as reactive.

      • Stillbirth rates have been shown to be significantly lower after a reactive trace than after a non-reactive trace6.

      • CTG interpretation is open to inter- and intra-observer variation but can be interpreted by computerised analysis. CTG should not be used as the only form of surveillance of a high-risk pregnancy7.

      • A contraction stress test, carried out during induced contractions using oxytocin, has no clinical benefits, and a false positive rate as high as 50%; it may also have significant adverse effects8. It is not used in the UK.

    • Intrapartum CTG:

      • See the separate Intrapartum Fetal Monitoring article for details.

      • CTG should not be used routinely as part of the initial assessment of low-risk women in early labour9.

      • No decision about a woman's care should be made on the basis of CTG findings alone10.

  • Biophysical profile (BPP) is time-consuming and rarely abnormal in the presence of normal umbilical arterial Doppler. It consists of a combination of CTG, fetal behaviour (including movement, tone and breathing) and amniotic fluid volume. This produces a BPP score to predict the degree of any compromise to the fetus. Available evidence does not support its routine use in high-risk pregnancies but observational data suggest it has good negative predictive value for fetal compromise6.

  • Amniotic fluid volume, both oligohydramnios and polyhydramnios, has been shown to be associated with poor fetal outcomes. However, oligohydramnios is itself associated with intrauterine growth restriction and urogenital malformations, which were not controlled for in the studies, demonstrating an association with poor outcomes. Polyhydramnios, when clinically apparent, is related to poor neonatal outcomes but mild, idiopathic polyhydramnios, detected only on ultrasound, is not associated with adverse outcomes.

  • Fetal scalp blood sampling during labour, to measure lactate (in preference to pH if available), may be indicated for an abnormal intrapartum CTG10. See the separate Intrapartum Fetal Monitoring article for details.

A composite risk score, based on fetal Doppler flow resistance indices, has shown promise in identifying those fetuses antenatally who develop fetal distress intrapartum11.


There have been no recent trials of operative versus conservative management of suspected fetal distress12.

  • Signs of antenatal fetal distress require monitoring with a view to induction of labour or planned caesarean section.

  • Immediate delivery of a preterm fetus with suspected fetal distress may reduce the risk of intrauterine hypoxia but increases the risks associated with prematurity. Benefit may be gained by deferring delivery, especially if there is uncertainty; however, evidence is lacking to guide this decision13.

  • Continuing fetal distress during labour may indicate the need for delivery to be expedited. Speed of delivery should take into account the severity of fetal heart rate and blood sampling abnormalities and relevant maternal factors.The urgency of caesarean section should be documented using the following standardised scheme in order to aid clear communication between healthcare professionals about the urgency of a caesarean section14.

  • Class 1: immediate threat to the life of the woman or fetus. Perform this as soon as possible after decision. 30 minutes is an appropriate audit standard.

  • Class 2: maternal or fetal compromise which is not immediately life-threatening. In most situations, within 75 minutes of making the decision14. However, this is not achieved in a substantial proportion of cases, although it is uncertain how significant this is clinically15.

    • There is some evidence that very short 'decision-to-incision' time (<20 minutes) may be inversely proportional to neonatal outcomes, ie lower umbilical pH and Apgar scores16.

  • Amnioinfusion has been shown to be beneficial in suspected umbilical cord compression (particularly when there is oligohydramnios), with a reduced risk of caesarean section17:

    • In this process, sodium chloride or Ringer's lactate is infused transcervically or, if the membranes are still intact, via a needle inserted under ultrasound guidance through the uterine wall.

    • The potential adverse effects include umbilical cord prolapse, uterine scar rupture and amniotic fluid embolism.

    • The current evidence on the safety and efficacy of this procedure means it is not recommended in the UK for intrauterine fetal resuscitation10; it is only undertaken under special arrangements that include audit and research18.

  • Term or post-mature fetuses may produce meconium-stained liquor. Meconium can be detrimental to the fetal lungs by producing a chemical pneumonitis if inhaled:

    • Significant meconium is defined as dark green or black amniotic fluid that is thick or tenacious, or any meconium-stained amniotic fluid containing lumps of meconium10:

      • If significant meconium is present, fetal blood sampling and advanced neonatal life support may be required at delivery.

      • If there has been non-significant meconium, the baby should be observed at one and two hours.

    • Amnioinfusion has been used to reduce the risk of meconium aspiration by diluting the meconium present; however, it is unclear whether this is beneficial and it is not used in routine practice19.

Further reading and references

  • Martis R, Emilia O, Nurdiati DS, et al; Intermittent auscultation (IA) of fetal heart rate in labour for fetal well-being. Cochrane Database Syst Rev. 2017 Feb 13;2:CD008680. doi: 10.1002/14651858.CD008680.pub2.
  • Devane D, Lalor JG, Daly S, et al; Cardiotocography versus intermittent auscultation of fetal heart on admission to labour ward for assessment of fetal wellbeing. Cochrane Database Syst Rev. 2017 Jan 26;1:CD005122. doi: 10.1002/14651858.CD005122.pub5.
  • Hilal Z, Mrkvicka J, Rezniczek GA, et al; Accuracy of intrapartum fetal blood gas analysis by scalp sampling: A retrospective cohort study. Medicine (Baltimore). 2017 Dec;96(49):e8839. doi: 10.1097/MD.0000000000008839.
  1. Caesarean birth; NICE Clinical Guideline (March 2021 - last updated January 2024)
  2. Chauhan SP, Magann EF, Scott JR, et al; Cesarean delivery for fetal distress: rate and risk factors. Obstet Gynecol Surv. 2003 May;58(5):337-50.
  3. MacLennan AH, Thompson SC, Gecz J; Cerebral palsy: causes, pathways, and the role of genetic variants. Am J Obstet Gynecol. 2015 May 21. pii: S0002-9378(15)00510-4. doi: 10.1016/j.ajog.2015.05.034.
  4. Gordon A, Raynes-Greenow C, McGeechan K, et al; Risk factors for antepartum stillbirth and the influence of maternal age in New South Wales Australia: a population based study. BMC Pregnancy Childbirth. 2013 Jan 16;13:12. doi: 10.1186/1471-2393-13-12.
  5. Bond DM, Gordon A, Hyett J, et al; Planned early delivery versus expectant management of the term suspected compromised baby for improving outcomes. Cochrane Database Syst Rev. 2015 Nov 24;(11):CD009433. doi: 10.1002/14651858.CD009433.pub2.
  6. Reduced Fetal Movements; Royal College of Obstetricians and Gynaecologists (February 2011)
  7. The Investigation and Management of the Small-for-Gestational-Age Fetus; Royal College of Obstetricians and Gynaecologists Green-top guideline (updated January 2014)
  8. S1-Guideline on the Use of CTG During Pregnancy and Labor: Long version - AWMF Registry No. 015/036; Geburtshilfe Frauenheilkd. 2014 Aug;74(8):721-732.
  9. Intrapartum care; NICE Quality Standard, December 2015 - last updated February 2017
  10. Intrapartum care for healthy women and babies; NICE Guideline (Dec 2014 - updated Dec 2022)
  11. Prior T, Mullins E, Bennett P, et al; Prediction of fetal compromise in labor. Obstet Gynecol. 2014 Jun;123(6):1263-71. doi: 10.1097/AOG.0000000000000292.
  12. Hofmeyr GJ, Kulier R; Operative versus conservative management for 'fetal distress' in labour. Cochrane Database Syst Rev. 2012 Jun 13;6:CD001065. doi: 10.1002/14651858.CD001065.pub2.
  13. Stock SJ, Bricker L, Norman JE, et al; Immediate versus deferred delivery of the preterm baby with suspected fetal compromise for improving outcomes. Cochrane Database Syst Rev. 2016 Jul 12;7:CD008968. doi: 10.1002/14651858.CD008968.pub3.
  14. Caesarean section; NICE Clinical Guideline (November 2011 - last updated September 2019)
  15. Tolcher MC, Johnson RL, El-Nashar SA, et al; Decision-to-incision time and neonatal outcomes: a systematic review and meta-analysis. Obstet Gynecol. 2014 Mar;123(3):536-48. doi: 10.1097/AOG.0000000000000132.
  16. Hillemanns P, Strauss A, Hasbargen U, et al; Crash emergency cesarean section: decision-to-delivery interval under 30 min and its effect on Apgar and umbilical artery pH. Arch Gynecol Obstet. 2005 Dec;273(3):161-5. Epub 2005 Jul 26.
  17. Hofmeyr GJ, Lawrie TA; Amnioinfusion for potential or suspected umbilical cord compression in labour. Cochrane Database Syst Rev. 2012 Jan 18;1:CD000013. doi: 10.1002/14651858.CD000013.pub2.
  18. Therapeutic amnioinfusion for oligohydramnios during pregnancy (excluding labour); NICE Interventional Procedure Guidance, November 2006
  19. Hofmeyr GJ, Xu H, Eke AC; Amnioinfusion for meconium-stained liquor in labour. Cochrane Database Syst Rev. 2014 Jan 23;(1):CD000014. doi: 10.1002/14651858.CD000014.pub4.

Article History

The information on this page is written and peer reviewed by qualified clinicians.

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