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"Can I just listen to the baby's heart?
Mrs.Christine Harding, Consultant Midwife, Hampshire Hospitals NHS Foundation Trust
I am talking about differing practices of intermittent auscultation (IA) of the fetal heart (FH). There have been problems associated with some practices requiring investigation.
Auscultation dates back to 1816; IA became the standard in the early 1900s, and was to a substantial extent replaced in the late 1960s by electronic fetal monitoring (EFM). The last can lead to more intervention in low risk labours without any benefit for the babies, and fetal monitoring remains a significant theme within the risk agenda. It is prominent in cases of stillbirth where the fetal heart was normal at the onset of labour. Litigation became more common with EFM mostly held responsible, but there was a lack of detailed consistent information about how IA should be carried out and little was done to guide practice".
Mrs. W., categorised as low risk, went into her fourth labour at home; it was to be a planned water birth with two midwives in attendance. No risk factors were identified. The FH was checked after contractions for one minute every 15 minutes, and an ambulance was called when recurring decelerations, believed to be early, were observed. She was not transferred to hospital as she was found to be in second stage; FH observations every 5 minutes caused the midwives no concerns. After 2 hours of the second stage, including both passive and active stages, the baby was born in poor condition and sadly died
Were the midwives clear about the risk factors they were looking for? After quick second stages in previous labours this one was very prolonged and should have raised concern.
Mrs. A, having her first baby and assessed as low risk, chose to deliver in a co-located centre. At 39 weeks she was transferred to the obstetric unit with reduced fetal movements. Cardiotocography (CTG) was normal on two consecutive days, and the fetal movements had improved. 10 days later she attended the birth centre in labour. The cervix was 3 cms. dilated; the midwife, recording a range, observed FH rates between 160 and 177 per minute and was advised by a senior midwife to set up fluid infusion to prevent dehydration. The FH slowed to between 120 and 138 and was later inaudible; the woman was transferred to the obstetric unit where intrauterine fetal death was confirmed.
Here the midwife can't have been monitoring the baseline of the fetal heart because she was recording a range and therefore may have missed the subtle changes which indicate the baby was compromised.
Now I wanted to promote safe, consistent IA practice and to simplify the skill and so increase the confidence of midwives. I set up a project with the help of others in Oxford. Local practice was reviewed and audited there was a broad range of practice among local midwives - and I did a search of the literature. The project involved me in teaching, devising prompts and writing a guideline.
In order to carry out this vital assessment clinicians need to have a good understanding of the normal physiology of fetal heart rate changes during labour. IA assessment should not try to replicate EFM assessment. We have depended on expert opinion on the time intervals for carrying out IA, and when to listen in relation to a contraction. A trial carried out some years ago asked clinicians to identify FH rate changes in recordings played to them (Miller). They were unable to identify the types of decelerations or variability, and only succeeded in identifying the baseline and accelerations.
Perhaps the midwife in the case of Mrs. A was trying to quantify FH variability, and believed that the variability she heard reassured her about the baby's condition. Some of the midwives I interviewed were using a system in which the rates were recorded several times within a minute; the inevitable apparent variability was equated with good fetal condition. This system, however, has been documented in literature in respect of identifying accelerations, and there is no published recommendation for it to measure variability.
Listening skills remain key; use your Pinard, and if you must use a doppler, cover the screen and listen. And NB: the CTG machine is not licensed for IA.
The signs of hypoxia. Variable decelerations. The baby stops moving to conserve its energy (so no accelerations). Adrenaline is released with increased heart rate; the depth and duration of decelerations increase; and there is loss of variability (sympathetic and parasympathetic systems affected), and finally prolonged bradycardia due to hypoxia of the cardiac muscle.But if we concentrate on variability we risk missing the rising baseline, the indicator of the early stages of hypoxia.
Edwin Chandraharan has made recommendations for practice1 in three steps.
Step one. Initial assessment of fetal wellbeing. Ensure that we have the right form of monitoring for the right mother and baby. Has fetal growth been good? Is there good liquor volume? Has the pregnancy been normal up to now? Has the pattern of fetal movements been normal? We have to be sure we are hearing the FH, so we palpate the uterus to find the optimal place in which to listen. Now we listen in three stages (in any order): baseline can be assessed by counting between contractions for at least 60 seconds, when the baby is still; listening for accelerations during episodes of fetal movement is vital in determining a well fetus (Gibb and Arulkumaran 20082); and listen immediately after a contraction has ended, confirmed by your palpation, not the mother's word, to exclude decelerations. Of course your observations of the mother are important. These baseline steps are as efficient an assessment of impending or actual hypoxia as a CTG on admission. We need to be sure that we have a well baby at the start.
Step two: continuous assessment of the whole picture. What is the woman's position, the quality of her contractions, is she dehydrated? Repeat recordings of the baseline as above, noting the trends if you have heard a deceleration or acceleration until the FH has settled, and enter them in the partogram. Whatever the deficiencies of the partogram may for maternal progress in labour, the baseline recorded on it is really important for fetal wellbeing. Recording the maternal pulse, preferably at the same time as the FH, is well worth while; uncertainty whether you are hearing one or the other requires CTG. The frequencies of observations should be every 15 minutes in the first stage of labour and every 5 minute in the active second stage, when there is increased potential for hypoxic stress.
Step three: documentation. This must include the initial assessment at whatever stage of labour the mother is first examined, with a thorough risk assessment; evidence of how observations of the FH are made, and of discussion with the woman and your recommendation for IA. Make a description of how IA is implemented, including the equipment used; include partogram evidence of the baseline rate and periodic comments in the records concerning contractions, presence or absence of accelerations and decelerations. Record also FH abnormality heard and any abnormal findings, plan of care and your reason for recommending EFM. If ultimately you cannot be reassured, move away from IA.
Act if there is difficulty in hearing the FH; if the mother's pulse and FH are so similar that you are not absolutely sure you have two different rates; if the baseline is abnormal or rising as plotted on the partogram; if you hear any decelerations and of course if risk factors develop.
What are you to do? These are the possibilities: increase the frequency of auscultation; think about the whole picture and look for a cause; call for help; recommend EFM and consider transfer to the obstetric unit.
The project led to a great improvement in compliance with standards and documentation; the midwives felt much more confident in their work and in teaching others, and there were an increase in their understanding of how to carry out IA intelligently and a reduction in serious incidents. We have instituted annual review, written an IA quiz, devised posters and I've produced a pocket guide.
References to the text
1. Chandraharan E (2010) Rationale approach to electronic fetal monitoring during labour in 'all' resource settings. Sri Lanka Journal of Obstetrics and Gynaecology. 32 pp77-84
2. Gibb D, Arulkumaran S (2008) Fetal Monitoring in Practice. Third edition Churchill Livingstone.
American College of Obstetricians and Gynecologists (ACOG) (1995) Fetal heart rate patterns: Monitoring, interpretation and management. Technical Bulletin 209 Washington DC
Alfirevic Z, Devane D, Gyte GML(2008) Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. The Cochrane Library Issue 4
Lowe V, Harding C (2013) Intermittent Auscultation. In: Sir Sabaratnam Arulkumaran, Jaydeep Tank, Rohana Haththotuwa and Parikshit Tank. Antenatal and Intrapartum fetal Surveillance. Universities Press (India) Private Limited
Liston R, Sawchuck D, Young D (2007) Intrapartum Fetal Surveillance. Fetal Health Surveillance: Antepartum and Intrapartum Consensus Guideline. Journal of Obstetrics and Gynecology Canada 29(9):s25-54
Miller FC, Pearce KE, Paul RH (1984) Fetal Heart Rate Pattern recognition by the Method of Auscultation. Obstetrics and Gynecology. 64 (3) pp 332-336
NCCWCH. 2007. National Collaborating Centre for Women's and Children's Health. Intrapartum care: Care of healthy women and their babies during childbirth. London: RGOG Press
Paine LL, Payton RG, Johnson RB (1986) Auscultated Fetal Heart Rate Accelerations. Part 1. Accuracy and Documentation. Journal of Nurse-Midwifery. 31 (2) pp68-72
Schifrin BS, Amsel J, Burdorf G (1992) The accuracy of auscultatory detection of fetal cardiac decelerations: A computer simulation. American Journal of Obstetrics and Gynecology. 166 pp 566-76
The SHIP trial (Self-Hypnosis for Intrapartum Pain) – feasibility issues.
Kenneth Finlayson, Research Assistant, University of Central Lancashire.
Hypnosis is the induction of a deeply relaxed state with increased suggestibility and the suspension of critical faculties” (British Medical Journal – BMJ, Vickers & Zollman 1999 ). The hypnotist has direct access to the subject's subconscious; this enables the insertion of information to change their behaviour or experience. Electroencephelographic (EEG) studies suggest that brain wave patterns are altered in hypnosis to the theta mode –, deeply relaxed yet still attentive e.g. the driver who “forgets” a length of the road he has just covered. Heart rate and blood pressure are reduced, as is the blood cortisol.
A 1999 review of research (BMJ, as above) suggested that hypnosis is effective in someconditions associated with anxiety (asthma, irritable bowel syndrome), in some mental health conditions (panic attacks, phobias), and the pain of childbirth. Further reviews confirmed this, while others have doubted the efficacy of hypnosis in labour reducing the use of medicines and epidural analgesia.
(See references below)
Our SHIP trial is a randomised, non-blinded study with a self-hypnosis training package. There are two 1.5 hour training sessions at 32 and 35 weeks and a 25-minute training CD, which reinforces the self-hypnosis messages; this is supplied at the first session and is intended for daily use until term. Our main outcome measure will be a comparison of epidural use between self-hypnosis (343 women) and control (337) – usual care – groups, recruited in maternity units in north-west England; Blackburn, Burnley, Liverpool and Preston are the centres collaborating. There are questionnaires at baseline (27 weeks), 36 weeks and then at 2 and 6 weeks postpartum, analysis of the last of which will be completed soon. We hope for a return rate for these of about 70%. An attendance rate of 80 to 85% across the two sessions seems satisfactory. The incidence of serious events in pregnancy, labour and postpartum have been within the expected range.
We are interested to know the perceptions of and attitudes to hypnosis of all maternity staff throughout the involved trusts, and have sent them questionnaires. Some of them are somewhat daunted when women arrive deeply relaxed in strong labour! I am interviewing the mothers who undertook self-hypnosis training to explore their opinions on hypnosis and their birth experiences, and I will be running focus groups with the midwives who conducted the hypnosis sessions to discuss the training they both receive and give to the women.
How does research such as this contribute to the feasibility of the use of hypnosis? The issues include the design of trials, the susceptibility of subjects to the phenomenon, its practice, and the significance of the outcome measures. In terms of design be aware that there are considerable differences in the training for hypnobirthing, which is – longer, and more intensive, often with one to one support. We must accept that the method we have investigated is a compromise. It is of some importance to learn, if possible, how susceptible the women in such a trial as ours are to hypnosis, and scales to assess this are available . Some of them are elaborate, others slightly weird in their choice of questions, but to justify the costs involved in providing a self-hypnosis service we need to know how easy or difficult it is to hypnotise women and whether hypnotic susceptibility can be correlated with birth experience. The hypnotisability test we used was a validated scale (the Tellegen Absorption Scale - http://socrates.berkeley.edu/~kihlstrm/TAS.htm) and it has been said that 'by any standard, the most frequently studied correlate of hypnotisability is absorption, or "openness to absorbing and self-altering experiences”' (Tellegen & Atkinson, 1974). The commitment we ask of the participating women is considerable, and on top of all that we ask them how often they practise self-hypnosis, so that this too can be correlated with the outcomes. And what were the outcomes where we combine susceptibility and practice? The question remains to be answered.
In order to capture the holistic properties of self-hypnosis, a range of clinical and non-clinical outcome measures must be considered. These include: the physiological – use of epidural or pharmaceutical analgesia, the Visual Analogue Scale (VAS) of pain, induction and length of labour; and the emotional – the EQ5D (Quality of Life) instrument, the Spielberger State-Trait Anxiety Inventory, the Edinburgh Depression Scale, the Satisfaction with Life Scale, the Mother Generated Index (MGI), and of course the expectations and experiences of labour of the mothers. Naturally some of these (e.g. the VAS) are not appropriate for use when a woman is in deep relaxation, and are therefore used retrospectively.
Some of our difficulties were trial-related: recruitment of women, which improved with more volunteer help and when we realised that replacing the word “hypnosis” with “deep relaxation” in our participant literature generated more interest. Some women associated the word 'hypnosis' with being out of control - the opposite of what we were trying to achieve with the training sessions. Poor return of questionnaires needed some encouragement on our part, with telephone reminder calls postnatally becoming necessary.
We must consider the holistic possibilities of hypnosis in childbirth; does it for example reduce the incidence of postnatal depression? This requires the method to be both quantitative and qualitative and we have found that this approach inevitably leads to additional costs.
1. Cyna AM, McAuliffe GL, Andrew MI. Hypnosis for pain relief in labour and childbirth: a systematic review. British Journal of Anaesthesia; 2004;93:505-11
2. Smith CA, Collins CT, Cyna AM, Crowther CA. Complementary and alternative therapies for pain management in labour. Cochrane Database of Systematic Reviews 2006; CD003521
3. Jones L, Othman M, Dowswell T, Alfirevic Z, Gates S, Newburn M, et al. Pain management for women in labour: an overview of systematic reviews. Cochrane Database of Systematic Reviews 2012;3; CD009234
Werner A, Uldbjerg N, Zachariae R, Rosen G, Nohr E. Self-hypnosis for coping with labour pain: a randomised controlled trial. BJOG 2012; DOI: 10.1111/1471-0528.12087
Protecting the perineum in the second stage.
Professor Lisa Kane Lowe, coordinator of the Nurse Midwifery programme, University of Michigan.
Basically we all want to move from a smooth supported birth to the woman enjoying her baby, ideally avoiding the “mucking about” that can follow, the repairs. It boils down to the prevention of perineal trauma, and in particular pelvic floor damage with its long term implications, the leaking and things falling out (incontinence and prolapse). And here we have to face the requests for elective caesarian section (CS) as a preventative, despite the lack of evidence for its effectiveness. There's a common narrative in consumer information which promotes reasons to avoid vaginal birth with prolonged pushing.
Think of the perineal body and the deeper levator muscles which support the uterus; the issues are muscle tearing and the possiblity of nerve compression or other injury. This muscle stretches two and a half times its length:
Many women undergo this stretch with no subsequent problem, while detachment of that muscle from its bone insertion leads to loss of support, with vaginal cosmetic surgery becoming an increasingly common resort. Young women are choosing elective CS to avoid this outcome.
So what's the opportunity for prevention? Urogynaecologists refer to the “inevitable problem”, while I prefer the “preventable problem”. There is normal change and recovery, but there are risk factors, based often on retrospective chart review: the baby's head circumference, maternal age, use of forceps, extensions of episiotomy with or without extension, 3rd and 4th degree lacerations, and the length of the second stage (extremes - less than 30 mins, more than 150 mins). I like to consider what is modifiable and worth our attention, and what is not modifiable. But there is a tendency to resort to interventions for which there is no evidence as the time taken during the birth process increases, and thus time is implicated in second stage pelvic floor damage.
Now I'm coming to the final stretch as a baby is born, when the decisions on clinical management have to be made. I am fortunate to have a fine interdisciplinary research team: urogynaecologists, obstetricians, bio-engineers, advanced practice nurses who work in pelvic floor clinics, and increasingly midwives; so we have to learn to use language which is understood across the team. Our objective is the promotion of physiological processes which support optimal outcomes for mothers and babies. For this we need to identify the preventable birth activities, aside from interventions such as instrumental delivery, which can lead to pelvic floor changes for some women, requiring change in management or referral for other expertise.
A central activity of the team is trying to understand how muscle stretch is facilitated. These muscles have to accommodate to the stress and strain to which they are being subjected; feeling the pressure and relaxing into it may by such accommodation allow the harmless stretch needed. It has been shown that the slow controlled stretch achieved by delivery between contractions can permit this (Cochrane Review, Albers).
We had trained doulas, familiar with the birth environment and well able to avoid being intrusive as observers, with a Day 1 assessment afterwards. The process through to the crowning of the head is familiar; significant for trauma are the duration of this and perineal blanching, implying a lack of blood supply to the tissue and a potential risk of tearing. Detailed recording of the observations became complicated (my neurotic need!), but its interpretation gave us the key factors related to perineal change leading to negative outcomes, the most significant being duration of stretch over time, particularly if there was prolonged failure to progress. Slow but continuous progress (muscle stretch/accommodation, stretch/accommodation) seemed to be most advantageous, with better outcome. Is there an ideal rate of change?
Our observations were helpful when they enabled us to correlate second degree perineal lacerations with little or no progress over time and accommodation delayed, but there was no supporting evidence for provider activity such as perineal massage and other interventions. Clearly associated with tearing were skin blanching and oedema, the appearance of blood (incipient laceration), and prolonged time with the fetal vertex visible but not progressing. We are moving on to the use of video associated with computer modelling.
Prospective and randomised trials of various treatments to minimise the incidence of lacerations have shown some benefit, although none were superior to the others and we were unable to confirm advantage for some. They have included warm compresses, massage with lubricant, and hands off the perineum until crowning. It is important to react to warning signs such as skin blanching by holding off pushing (if possible). Achieving success with slow pushing between contractions, consistent with the muscle physiology, depends on good communication between provider and woman, and remains the best opportunity for prevention of tears. Albers et al (20061 ) have identified valsalva pushing (straining with closed larynx) and prior suturing as predictors of trauma which offer options for change (i.e. avoid suturing in first births if possible). Although Dahlen et al (20072 ) concluded that primiparity, instrumental birth, heavier babies and being of Asian ethnicity are associated with increased rates of severe trauma, another trial could not confirm the last of these causes. Likewise our MRI scans of women “with severe risk factors” for trauma only confirmed the prediction in 25%. Increasing maternal age and the duration of pushing are confirmed factors for trauma, neither open to being modified.
When considering best practices related to the risk of childbirth-associated pelvic floor changes, age should be considered as well as attention to the duration of active pushing. There are no clear cut points for these, but they are features of the clinical factors to be considered. It remains to be confirmed if passive descent alternating with active pushing is potentially protective against negative pelvic floor changes.
Despite our knowledge of the risk factors for pelvic floor trauma we must do all we can to avoid engendering fear of it in the women for whom we are caring.
1. Albers LL, Sedler KD, Bedrick EJ, Teaf D, Peralta P. Factors related to genital tract trauma in normal spontaneous vaginal births. Birth. 2006 Jun;33(2):94-100.
2. Dahlen H, Ryan M, Homer C, Cooke M, 2007. An Australian prospective cohort study of risk factors for severe perineal trauma during childbirth. Midwifery, vol 23, no. 2, pp 196-203.
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