The Pinard Stethoscope

The Pinard Stethoscope

So here’s something that will be pretty mind-boggling for my UK readers: in the US, the Pinard stethoscope doesn’t really exist, at least not in any of the midwifery circles I travelled in.  NO ONE used it.  I’d never seen one or even heard of it until I moved here and started midwifery school (in fact, the only mention I can find of it in any of my American midwifery books–including my American midwifery textbooks–is a brief mention of it on page 112 in Ina May Gaskin’s Birth Matters, where it’s called the Pinard Horn rather than the Pinard stethoscope).  So you can imagine my surprise when I discovered that here in the UK, the Pinard stethoscope is a beloved midwifery tool, so much so that it serves as the logo for the Association of Radical Midwives, and beautiful wooden models are often given to newly qualified midwives as graduation gifts. Nearly every UK midwife owns a Pinard stethoscope–many of them even own several–and if that doesn’t convince you of its importance, it’s one of the first things Jenny pulls out of her midwifery bag during her visits on Call the Midwife.

All of this was news to me, though, as the closest thing we have to the Pinard stethoscope in the US is a fetoscope, which looks like this:

And you can see America’s most famous midwife, Ina May Gaskin, using a fetoscope here:

However, when I brought my American-style fetoscope to antenatal visits to show to my mentor, she was rather shocked, as she’d never seen one before. We then spent the afternoon experimenting with the Pinard stethoscope v. the fetoscope for auscultation of the fetal heart. I found that I could hear the fetal heartbeat more clearly with the fetoscope, while she preferred the Pinard. Go figure! But it was a very interesting experiment, and generally the pregnant women who so graciously allowed us to practice auscultation on their beautiful bellies were amused by the whole thing.

Since I knew virtually nothing about the Pinard stethoscope, and since as a student here in the UK we’re required to become proficient with its use as per the standards for pre-registration midwifery education (NMC, 2009), I thought it would be a good topic to write about for my first midwifery school essay assignment (which, interestingly enough, are called “assessments” here, rather than “essays”, just for the record). So, having written 15 pages on the subject now, and having tried my hand at it multiple times in the clinical setting, I have a bit more of a clue with regards to this ancient and much-revered midwifery tool, which I’m going to share here (you lucky devils, you!).

The Pinard stethoscope is a small 6-8” hollow, funnel-shaped tube often made of wood, metal or plastic, with the larger end placed against the woman’s abdomen and the auscultator’s ear placed against the smaller end (Harrison, 2004). In pregnancy, the Pinard stethoscope can be used from approximately 24 weeks onwards to auscultate the fetal heart during antenatal visits, and can be used in labour as a tool for intermittent auscultation (Johnson & Taylor, 2016). The very first monoaural stethoscope was invented in 1819 René Laennec, and was basically a long wooden tube which the auscultator would place against the patient’s chest wall, with his/her ear placed against the other end (although who’re we kidding…in 1819, it was most likely a man’s ear on the listening end).  Prior to Laennec’s invention of the monoaural stethoscope, fetal auscultation was performed by the examiner placing his (or her) ear directly against the woman’s skin and listening through her abdomen, a practice which required a large degree of intimacy between patient and practitioner, and which (you can imagine) may have been particularly discomfiting to 19th Century sensibilities (Montagu, 2008; Blincoe, 2005). The Laennec stethoscope afforded a measure of distance between patient and practitioner, helping to preserve the dignity of both, and in 1821, Laennec’s colleague, Jacques Kergaradec, applied the newly invented stethoscope to fetal auscultation for the very first time (Pinkerton, 1969). John Creery Ferguson brought fetal auscultation to the British Isles after studying in Paris with Laennec and Kergaradec, where the practice quickly took root at the Rotunda Hospital in Dublin, gradually spreading to the rest of the UK from there (Pinkerton, 1980; Harrison, 2004). The Laennec stethoscope underwent modifications by Holh in 1834, and was finally refined by Adolfe Pinard in 1896 into the current model (Harrison, 2004; Dunn, 2006). The Pinard stethoscope transmits fetal heart sounds more clearly through the long bore of the tube than the more ubiquitous binaural stethoscope which we commonly see slung around practitioner’s necks, which is one of the reasons it still remains in use as a modern obstetric tool today (Montagu, 2008). And, since the advent of the Midwives Act in 1902 here in the UK, proficiency with the Pinard stethoscope been taught to midwives in the United Kingdom for over a century now.

So why use a Pinard stethoscope? What are the advantages to it, versus the more common doppler (which uses ultrasound technology)? And how does Pinard use slot into general antenatal and intrapartum care here in the UK? Good questions, and as luck would have it, this was exactly what I was writing about in my essay!

At its most basic level, the rationale underpinning fetal auscultation is to confirm the presence or absence of a fetal heart rate (FHR) and to assess fetal well-being (Johnson & Taylor, 2016). According to the National Institute of Health and Care Excellence (NICE) Guidelines (sort of the US’ NIH equivalent), there is limited benefit from routine FHR auscultation during antenatal visits, particularly in the presence of fetal movement, since “auscultation of the fetal heart may confirm that the fetus is alive but is unlikely to have any predictive value, and routine listening is therefore not recommended” (NICE, 2008). Nevertheless, NICE supports antenatal FHR auscultation if the mother requests it, and for better or worse, FHR auscultation has become an expected and routine part of antenatal care these days–I couldn’t imagine an antenatal visit in which a mother didn’t want to hear her baby’s heartbeat (once the pregnancy had advanced to the point that this is possible). In labour, FHR auscultation is recommended throughout in order to monitor fetal well-being and the fetal response to contractions (Johnson & Taylor, 2016). The NICE Intrapartum Care for Healthy Women and Babies Guideline (2014) recommends intermittent auscultation every fifteen minutes in the first stage and every five minutes in the second stage for all low-risk women in labour, with continuous cardiotocography (CTG–i.e. electronic fetal monitoring, in US speak) used only in high-risk women, or in situations where intermittent auscultation reveals a non-reassuring FHR pattern or other emerging risk factors (NICE, 2014).

The use of the Pinard stethoscope as a primary tool for fetal auscultation is supported by both NICE and the Royal College of Midwives (RCM). In its 2012 guideline on intermittent auscultation in labour, the RCM recommends that the Pinard stethoscope be used to initially auscultate the FHR before switching to hand-held Doppler or CTG (i.e. electronic fetal monitoring) in order to ensure that the fetal heart is being recorded accurately (RCM, 2012).  This is because unfortunately the Doppler is capable of picking up “artifact” and doubling or halving the maternal heart rate by mistake, and in many tragic situations Doppler ultrasound can falsely reassure both parents and practitioners that the baby is alive and well, when in fact that’s not the case (and many UK stores recently banned the sale of hand-held dopplers to customers because of this very thing).  Using a Pinard stethoscope first to confirm the presence of the fetal heart helps to limit this mistake, and in fact, the Medicines and Healthcare Products Regulatory Agency here in the UK has issued an advisory on CTG which calls for the Pinard stethoscope to be used initially and at any other point when a change in FHR or concern in labour arises, in order to prevent monitoring the wrong heart beat (MHRA, 2010).  NICE also specifies that either the Pinard stethoscope or Doppler ultrasound be used for the initial assessment of a woman in labour, rather than CTG, and that the Pinard is a valid tool for intermittent auscultation throughout labour (NICE, 2014).

There are many advantages to using the Pinard stethoscope. First of all, as mentioned above, the Pinard stethoscope allows the midwife to listen to the FHR directly, unlike Doppler technology which uses ultrasound technology “to evaluate changes in sound waves caused by the direction and velocity of blood flowing through vessels and the heart” (Blincoe, 2005) and which can sometimes get it wrong and pick up the maternal heart rate by mistake.  Many experienced practitioners also find that they are able to hear not only variability with a Pinard, but also differences in tone and rhythm which can be ascribed to differences in individual babies (ARM, 2000; Wickham, 2002a; Cronk, 2002), and in fact there have been reports of midwives being able to pick up congenital heart defects through the subtle changes in rate they were able to detect with the Pinard (ARM, 2000). The Pinard stethoscope may also help support the woman in her role as the expert on her baby (Young, 1999; Montagu, 2007). “The current fashion for selling Dopplers to pregnant women implies that artificial monitoring is in some way protective; instead, it disempowers women and casts implicit doubt on their ability to be conscious of their own baby’s well-being through …awareness of the baby’s movements” (Montagu, 2008, p. 3). In other words, we should all be working harder to support and empower women to feel like THEY are the experts on their babies (because they are) and reaffirming again and again that the biggest predictor of fetal well-being is fetal movement. If you can’t hear the FHR because the baby is moving too much–no problem! You know that the baby is absolutely fine, in that situation (although, unfortunately thanks the to the pressures of litigation, as a midwife these days you would still have to find and record the fetal heart rate, otherwise your care will be deemed sub-standard, and certainly wouldn’t hold up in a court of law).  The low-tech Pinard stethoscope exemplifies the art and essence of midwifery care, and is particularly valuable in the developing world where resources are more limited (Mahomed et. al., 1994). Similarly, there will always be women in the developed world who will decline ultrasound technology, and since it’s imperative that midwives respect a woman’s choices as per the NMC Code (2015) and the Better Births Initiative (National Maternity Review, 2016), the Pinard stethoscope offers a much needed alternative to the Doppler!

However, in practice, the Pinard stethoscope has several disadvantages as well.  First, it’s not easy to use in labour, particularly if the woman is moving around or assuming different positions, such as on hands and knees (Blake, 2008; Harrison, 2004). Second, the Pinard stethoscope can only be used from 24-28 weeks onward, whereas the Doppler can detect the FHR as early as 10 wks (Blake, 2008), which is a big advantage to the Doppler in many women’s books, since naturally many women want to hear their baby’s heart beat as early as possible. There is also concern that accurate FHR auscultation can only be achieved by a highly-skilled practitioner who is expert with the tool, and that the average user is not as accurate (Blake, 2008)–and I can certainly attest to that, as the Pinard stethoscope is quite tricky to use in the beginning.  Additionally, a randomised control trial (RCT) comparing Pinard stethoscope to Doppler or CTG found that the Pinard was the least successful in identifying abnormal FHR patterns (Mahomed et. al., 1994). You can’t use the Pinard stethoscope in the water, which means if you’re monitoring a woman with Pinards alone, she’d have to get out of her birth tub every time you needed to listen, which isn’t very practical.  Finally, women have reported that the use of the Pinard stethoscope in labour is more uncomfortable than the Doppler, particularly if you can only use the Pinard while she’s on her back; additionally, you sometimes have to press quite firmly with the Pinards in order to be able to hear the FHR, which again can be very uncomfortable in labour.  Overall, studies have shown that women tend to prefer Doppler or CTG monitoring instead of the Pinard stethoscope, as being able to hear the heart themselves provides them with more reassurance (Garcia et. al., 1985; ARM, 2000).

And in practice, what is it actually like? Well, rather tricky. It took me several tries with it before I could finally hear the fetal heart. It’s often a very faint sound, and in many cases I don’t really “hear” it at all, but instead almost “feel” it against my ear as a vibration, something which Mary Cronk has written about as well (Cronk, 2002). It also requires that you’re SPOT ON with your abdominal palpation, as you really have to be right on top of the fetal heart in order to be able to hear it (whereas the Doppler is a bit more forgiving, and can allow you to pick up the heart rate even if you’re not exactly in the right location).  This means that the Pinard is a lot more difficult to use in situations where the baby is fully engaged, breech or posterior, as well as in situations where it’s difficult to determine the baby’s position due to the mum having a higher BMI. On the flip side, however, because precise abdominal palpation is a prerequisite skill for using the Pinard stethoscope, many midwives will use the Pinard to help confirm that their assessment of fetal position is correct, and sometimes see this as an advantage to its use (Cronk, 2002; Montague, 2008; Wickham, 2002a).

All in all, there’s something really special about the Pinard stethoscope, and I’m very glad that I’ve had the opportunity to learn how to use it.  I like it because of its historical significance, as well as its low-tech simplicity. I also like that there’s a real art to its use that only comes from experience and continued skill development. To me it represents a true skill that must be learned and practiced many, many times in order to attain mastery, and is something I’ll have to continue to practice and refine for the remaining years of my career.  Now that I’m on my rotation in the Birthing Center, I’ve been relying on the Doppler more, particularly as we’ve been using the pools a lot and it’s impossible to use the Pinard in a pool, but I would absolutely like try the Pinard in labour as well. I would like to someday be as comfortable and proficient with the Pinard as I am with the Doppler–it’s worth aspiring to, at any rate!

 

References:

Association of Radical Midwives (ARM). (2000) ‘Hearing Variability’, Midwifery Matters, (84) [no page numbers].

Blake, D. (2008) ‘Pinards: out of use and out of date?’, British Journal of Midwifery, 16(6), pp. 364-365.

Blincoe, A. J. (2005) ‘Fetal monitoring challengs and choices for midwives’, British Journal of Midwifery, 13(2), ppp. 108-111.

Cronk, M. (2002) Me and my Pinard’s. Midwifery Matters, (94), pp. 3-4.

Dunn, P.M. (2006) ‘Adolphe Pinard (1844-1934) of Paris and intrauterine paediatric care’, Archives of Disease in Childhood, Fetal & Neonatal Edition, 91(3), pp. 79-85.

Garcia, J. et al. (1985) ‘Mother’s Views of continuous electronic fetal heart monitoring and intermittent auscultation in a randomized controlled trial.’ Birth, 12(2), pp. 79-85.

Harrison, J. (2004) ‘Auscultation: the art of listening’, RCM Midwives, 7(2), pp. 64-69.

Johnson, R. and Taylor, W. (2016) Skills for Midwifery Practice. 4th Edition. London: Elsevier.

Mahomed, K., Nyoni, R., Mulambo, T., Kasule, J. and Jacobus, E. (1994) ‘Randomised controlled trial of intrapartum fetal heart rate monitoring’, British Medical Journal, 308(6927), pp. 497-500.

Medicines and Healthcare products Regulatory Agency (MHRA) (2010) Fetal Monitor/ Cardiotograph (CTG) – Adverse Outcomes Still Reported. Available at: https://www.gov.uk/drug-device-alerts/medical-device-alert-fetal-monitor-cardiotocograph-ctg-adverse-outcomes-still-reported (Accessed: 11 May 2017)

Montagu, S. (2008) In defense of the Pinard. Midwifery Matters, (118), pp. 3-4.

National Institute for Health and Care Excellence (NICE) (2008) Antenatal Care for Uncomplicated Pregnancies. (Clinical Guideline CG 62). Available at: https://www.nice.org.uk/guidance/cg62/chapter/1-Guidance (Accessed: 19 May 2017)

National Institute for Health and Care Excellence (NICE) (2014) Intrapartum Care for Healthy Women and Babies. (Clinical Guideline CG 190). Available at: https://www.nice.org.uk/guidance/cg190 (Accessed: 11 May 2017)

Nursing and Midwifery Council (NMC) (2009) Standards for pre-registration midwifery education. Available at: https://www.nmc.org.uk/globalassets/sitedocuments/standards/nmc-standards-for-preregistration-midwifery-education.pdf (Accessed: 11 May 2017)

Nursing and Midwifery Council (NMC) (2015) The Code. Available at: https://www.nmc.org.uk/standards/code/ (Accessed: 15 May 2017)

Pinkerton, J.H.M (1969) ‘Kergaradec, Friend of Laennec and Pioneer of Foetal Auscultation’, Proceedings of the Royal Society of Medicine, 62(5), pp. 477-483.

Pinkerton, J.H.M (1980) ‘John Creery Ferguson: Friend of William Stokes and pioneer of auscultation of hte fetal heart in the British Isles’, British Journal of Obstetrics and Gynaecology, 87(4), pp.257-260.

Royal College of Midwives (RCM) (2012) Evidence Based Guidelines for Midwifery-Led Care in Labour: Intermittent Auscultation. Available at: https://www.rcm.org.uk/sites/default/files/Intermittent%20Auscultation%20%28IA%29_0.pdf (Accessed: 11 May 2017)

Wickham, S. (2002a) ‘Pinard wisdom: tips and tricks from midwives (Part 1)’ Practising Midwife, 5(9), pp. 21.

Wickham, S. (2002b) ‘Pinard wisdom: tips and tricks from midwives (Part 2)’ Practising Midwife, 5(10), pp. 35.

Young, G. (1999) ‘The case for community-based maternity care’, in Marsh, G. and Renfrew, M. (eds.) Community-based Maternity Care. Oxford: Oxford University Press, pp. 7-26.

Leave a Reply

%d bloggers like this: