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What does this mean anyway? I'm having images of bubs getting redder and redder and finally exploding but I'm pretty certain that's not what happens!
Can mum be feeling fine but baby still be distressed? Is it based only on the heart rate and how low it gets during labour? And is this due to mum's heart rate or BP?
Does foetal distress result in brain damage or organ damage if untreated (as in, it's not born asap)?
Good questions, I know someone smarter than me will be able to help you.
I think the only things they are really able to monitor with bubs are movements and heart rate. Jenna was going into some distress when the drs tried to turn her by hand inside me - her heart rate dipped after each effort.
I think another thing they keep an eye on is meconium in the amniotic fluid.
One handed atm but here goes...
:
Guide to Clinical Preventive Services, Second Edition
Prenatal Disorders
Intrapartum Electronic Fetal Monitoring
RECOMMENDATION
Routine electronic fetal monitoring for low-risk women in labor is not recommended. There is insufficient evidence to recommend for or against intrapartum electronic fetal monitoring for high-risk pregnant women (see Clinical Intervention).
Most fetuses tolerate intrauterine hypoxia during labor and are delivered without complications, but assessments suggesting fetal distress are associated with an increased likelihood of cesarean delivery (63% compared to 23% for all births).6 The exact incidence of fetal distress is uncertain; a rate of 42.9/1,000 live births was reported from 1991 U.S. birth certificate data, with the highest rates in infants born to mothers under age 20 or over age 40, and in blacks.7
Accuracy of the Screening Test
The principal screening technique for fetal distress and hypoxia during labor is the measurement of fetal heart rate. Abnormal decelerations in fetal heart rate and decreased beat-to-beat variability during uterine contractions are considered to be suggestive of fetal distress. The detection of these patterns during monitoring by auscultation or during electronic monitoring (cardiotocography) increases the likelihood that the fetus is in distress, but the patterns are not diagnostic. In addition, normal or equivocal heart rate patterns do not exclude the diagnosis of fetal distress.5 Precise information on the frequency of false-negative and false-positive results is lacking, however, due in large part to the absence of an accepted definition of fetal distress.8,9 For many years, acidosis and hypoxemia as determined by fetal scalp blood pH were used for this purpose in research and clinical practice, but it is now clear that neither finding is diagnostic of fetal distress.5,10-12
Electronic fetal heart rate monitoring can detect at least some cases of fetal distress, and it is often used for routine monitoring of women in labor. In 1991, the reported rate of electronic fetal monitoring in the U.S. was 755/1,000 live births.7 The published performance characteristics of this technology, derived largely from research at major academic centers, may overestimate the accuracy that can be expected when this test is performed for routine screening in typical community settings. Two factors in particular that may limit the accuracy and reliability achievable in actual practice are the method used to measure fetal heart activity and the variability associated with cardiotocogram interpretations.
The measurement of fetal heart activity is performed most accurately by attaching an electrode directly to the fetal scalp, an invasive procedure requiring amniotomy and associated with occasional complications. This has been the technique used in most clinical trials of electronic fetal monitoring. Other noninvasive techniques of monitoring fetal heart rate, which include external Doppler ultrasound and periodic auscultation of heart sounds by clinicians, are more appropriate for widespread screening but provide less precise data than the direct electrocardiogram using a fetal scalp electrode. In studies comparing external ultrasound with the direct electrocardiogram, about 20-25% of tracings differed by at least 5 beats per minute.13,14
A second factor influencing the reliability of widespread fetal heart rate monitoring is inconsistency in interpreting results. Several studies have documented significant intra- and interobserver variation in assessing cardiotocograms even when tracings are read by experts in electronic fetal monitoring.15-17 It would be expected that routine performance of electronic monitoring in the community setting with interpretations by less experienced clinicians would generate a higher proportion of inaccurate results and potentially unnecessary interventions than has been observed in the published work of major research centers.
And some more below. You will see heaps of stuff on this if you google Electronic Fetal Monitoring, it's well known that it is not 100% reliable nor recommended routinely.
:
Electronic fetal monitoring with the cardiotocograph is standard practice during labour in most obstetric units in the United Kingdom. The technique was introduced as a screening test in the 1970s in the belief that it would improve the detection of fetal hypoxaemia and reduce cerebral palsy and perinatal mortality, particularly in high risk pregnancies. Early retrospective observational studies supported the view that it was superior to intermittent auscultation using either a Pinard stethoscope or a hand held doppler ultrasound device.1 Its use spread rapidly from high risk to low risk pregnancies where the fetus is at least risk from hypoxic events in labour. Was this spread necessary or wise?
By the 1990s systematic reviews of randomised controlled trials of electronic fetal monitoring versus intermittent auscultation during labour had shown no effect on neonatal outcomes such as metabolic acidosis at birth, low Apgar scores or admissions to neonatal intensive care.2-4 An increase in neonatal seizures was seen in the group with intermittent auscultation but no long term increase in neurological problems.5
Electronic fetal monitoring did, however, have an effect on women in labour. Levels of obstetric interventionaugmentation of labour, epidural anaesthesia, instrumental delivery, and caesarean sectionconsistently increased.4 Instrumental delivery and caesarean section were even more common when electronic fetal monitoring was not backed up by fetal blood sampling. The impact on the mother and her experience of labour was therefore considerable, without any gain for the baby. In many units this evidence allowed a return to intermittent auscultation, which is less intrusive for the woman. Unfortunately the dramatic increase in litigation in obstetrics has tempered this change, as the cardiotocograph has also become an important legal document.
In low risk pregnancies adverse events during labour that affect the development of the baby are rare. Most cases of cerebral palsy have antecedents in the antenatal period,8 with only about 10% of cases having an intrapartum cause. The prevalence of perinatal mortality or cerebral palsy from intrapartum causes is about 0.8 per 1000 and 0.1 per 1000 respectively.1 Most studies of electronic fetal monitoring were underpowered to detect these rare events and have concentrated on more immediate fetal outcomes. When perinatal mortality was studied no effect was seen. Nevertheless, the cardiotocograph continues to be an important document in many legal cases concerning cerebral palsy.
So the evidence is strongly against the routine use of electronic fetal monitoring. This is further reinforced by the publication last month of the Royal College of Obstetricians and Gynaecologists' guidelines on electronic fetal monitoring, which have been developed with the National Institute for Clinical Excellence.1 This important document has brought together all the good evidence on electronic fetal monitoring. There are some important messages, which should affect practice on labour wards throughout Britain.
The chief recommendation is that intermittent auscultation is the most appropriate method of fetal monitoring for women in labour who are low risk. This allows the best compromise between assuring fetal safety and allowing the woman mobility and independence during labour. For auscultation to be successful it needs to be frequent, especially in the second stage of labour, and therefore requires one to one care of the woman. Unfortunately this is an ideal which may be impossible in hard pressed labour wards, where midwives are often in short supply. Ironically, there is good evidence that one to one care alone has a powerful effect on the labouring woman, reducing intervention.8 The cardiotocograph can become a surrogate for this best quality care and has a major impact on the caesarean section rate.
Thanks for all that info. Most helpful :)
No worries :) Here's the Cochrane Systematic review if you are interested also :)
:
The Cochrane Database of Systematic Reviews 2006 Issue 3
Copyright © 2006 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Plain language summary
Comparing continuous electronic monitoring of the baby's heartbeat in labour using cardiotocography (CTG, sometimes known as EFM) with intermittent monitoring (intermittent auscultation, IA)
Monitoring the baby's heartbeat is one way of checking babies' well-being in labour. By listening to, or recording the baby's heartbeat, it is hoped to identify babies who are becoming short of oxygen (hypoxic) and who may benefit from caesarean section or instrumental vaginal birth. A baby's heartbeat can be monitored intermittently by using a fetal stethoscope, Pinard (special trumpet shaped device), or by a handheld Doppler device. The heartbeat can also be checked continuously by using a CTG machine. This method is sometimes known as electronic fetal monitoring (EFM) and produces a paper recording of the baby's heart rate and their mother's labour contractions. Whilst a continuous CTG gives a written record, it prevents women from moving during labour. This means that women may be unable to change positions or use a bath to help with comfort and control during labour. It also means that some resources tend to be focused on the needs of the CTG rather than the woman in labour. This review compared continuous CTG monitoring with intermittent auscultation (listening). It found 12 trials involving over 37,000 women. Most studies were not of high quality and the review is dominated by one large, well-conducted trial of almost 13,000 women who received care from one person throughout labour in a hospital where the membranes have either ruptured spontaneously or were artificial ruptured as early as possible and oxytocin stimulation of contractions was used in about a quarter of the women. There was no difference in the number of babies who died during or shortly after labour (about 1 in 300). Fits (neonatal seizures) in babies were rare (about 1 in 500 births), but they occurred significantly less often when continuous CTG was used to monitor fetal heart rate. There was no difference in the incidence of cerebral palsy, although other possible long-term effects have not been fully assessed and need further study. Continuous monitoring was associated with a significant increase in caesarean section and instrumental vaginal births. Both procedures are known to carry the risks associated with a surgical procedure although the specific adverse outcomes have not been assessed in the included studies.
Abstract
Background
Cardiotocography (sometimes known as electronic fetal monitoring), records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic), so additional assessments of fetal well-being may be used, or the baby delivered by caesarean section or instrumental vaginal birth.
Objectives
To evaluate the effectiveness of continuous cardiotocography during labour.
Search strategy
We searched the Cochrane Pregnancy and Childbirth Group Trials Register (March 2006), CENTRAL (The Cochrane Library 2005, Issue 4), MEDLINE (1966 to December 2005), EMBASE (1974 to December 2005), Dissertation Abstracts (1980 to December 2005) and the National Research Register (December 2005).
Selection criteria
Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with (a) no fetal monitoring, (b) intermittent auscultation (c) intermittent cardiotocography.
Data collection and analysis
Two authors independently assessed eligibility, quality and extracted data.
Main results
Twelve trials were included (over 37,000 women); only two were high quality. Compared to intermittent auscultation, continuous cardiotocography showed no significant difference in overall perinatal death rate (relative risk (RR) 0.85, 95% confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n = 32,386, nine trials) although no significant difference was detected in cerebral palsy (RR 1.74, 95% CI 0.97 to 3.11, n = 13,252, two trials). There was a significant increase in caesarean sections associated with continuous cardiotocography (RR 1.66, 95% CI 1.30 to 2.13, n =18,761, 10 trials). Women were also more likely to have an instrumental vaginal birth (RR 1.16, 95% CI 1.01 to 1.32, n = 18,151, nine trials). Data for subgroups of low-risk, high-risk, preterm pregnancies and high quality trials were consistent with overall results. Access to fetal blood sampling did not appear to influence the difference in neonatal seizures nor any other prespecified outcome.
Authors' conclusions
Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The real challenge is how best to convey this uncertainty to women to enable them to make an informed choice without compromising the normality of labour.
So really we need to weigh up the chance of bubs having a seizure (and even then, the chances were only halved with continuous CTG)...hmmm, how does one do that?! What damage does a seizure do? Ah, too many questions!
At any rate, I have a plethora of information now which I shall make my DH and sister read....so thanks heaps Kelly!
Hehehe - if it helps any, I dont know anyone who's infant has has a seizure at birth. I am sure there'll probably be someone on BB but I never have come across one. As they said, it didn't effect the infant at all... so I would rather be up and active and have a shorter, less painful labour ;)