The Dreaded Third Degree Tear…

(March 2017)


On supporting a woman in labour who subsequently sustained a third degree tear, and the experience of significant feelings of guilt and hand-wringing, I have been reflecting on my role in the possible prevention of such a degree of trauma and then the support given to women following repair as well as the outlook for morbidity.

According to the Royal College of Obstetricians and Gynaecologists (RCOG), a third degree tear can be defined as “a tear that involves the muscle that controls the anus (the anal sphincter)” and affects on average 3% of women giving birth; broken down this equates to approximately 6% of primiparous women and 2% of multiparous women although the risk increases to 5-7% if they have sustained a previous third degree tear (2015). Clements (2001) takes a more conservative stance, estimating third and fourth degree tears to be more in the region of 1-2%.

Regardless of the percentile incidence, the reality is that the long term implications of suffering a third or indeed fourth degree tear are significant, including a higher risk of sexual dysfunction, faecal and flatus incontinence as well as the associated risks to mental and emotional health. It is however unfortunately well known that women are reluctant to seek help and support for problems relating to third degree tears (Glazener, 1997) and the outlook for these women, facing these issues unsupported, borders on tragic. With a disturbing 100% likelihood of anal incontinence in women with undetected sphincter injuries (Ferando et al, 2002), this places a great responsibility on the practitioners inspecting the perineum to identify third and fourth degree tears where they exist and then on the skill of the repairing Doctor.

So…?

The question is posed then, what responsibility lies with the midwife who is supporting the woman in labour? Can we prevent third degree tears? Some risk factors such as primiparity, ethnicity, shoulder dystocia and infants over 4kg (RCOG) would seem to be largely out of our control, and then others such as a longer 2nd stage and requiring an instrumental delivery may provide a wider remit for the midwife to have an impact. When any of these risk factors do come to bear however it is vital that inspection of the perineum is undertaken knowing that a severe tear is significantly more likely.
So in terms of exploring the midwife’s role in actually preventing the third and fourth degree tear from happening, there are the known midwifery strategies to reduce the incidence of a prolonged second stage – employing all of our knowledge and experience of facilitating a physiological birth in the minimising of the length of an active second stage as well as educating and preparing women for the same. Perineal massage in the third trimester and carrying out pelvic floor exercises may help to reduce the incidence of severe perineal trauma (Heidi et al, 2001) and so widening standard antenatal education to include this topic may well benefit women as well as ultimately reduce the cost to the NHS if the incidence of both instrumental birth and serious perineal trauma were to reduce. Kettle (2002) noted that continuous support in labour by a midwife can reduce the likelihood of an instrumental delivery and so the necessary battle cry of “More Midwives!” for this reason among so many others, must continue.

There has been much debate about ‘hands on’ or ‘hands poised/off’ and though the net research conclusion seems to be that there is no difference in outcome for ‘any’ perineal tearing, it seems widely accepted that the applying of warm packs is useful in reducing the incidence of anal sphincter injury (RCOG 2015, Dahlen et al 2007). A further short literature search shows that pushing while in the lateral position, intrapartum perineal massage, perineal pressure and compresses are given as some recommendations (Hastings-Tolsma et al 2007). Interestingly a study in 1996 (Albers et al) found that the use of oils increased perineal lacerations, I wonder if this increased the speed of the advancing fetal head and reduced the slow stretching necessary. Both studies reiterated that lithotomy is associated with greater perineal trauma including a higher incidence of episiotomy.

Water birth increases the risk?

There is some evidence to suggest that water birth increases the risk of third and fourth degree tears, attributable it is thought though not confirmed by robust evidence, to oedema of the tissues as well as poor visualisation by the midwife of the advancing fetal head (McPherson 2014). This is a finding I discovered in a number of publications (Lee & Cresswell 2013), and yet it is not a risk factor discussed widely or, in my experience, explained when a woman opts for water birth. It may be for some women that the increased chance of severe tears would outweigh the potential benefits such as pain relief and a shortened second stage – it should certainly be their choice to make. The RCM guideline for care of the perineum states very briefly that immersion in water doers not reduce the risk of anal sphincter injury and sadly does not elaborate nor give a subsequent recommendation either way(2012).

The unexpected case for smokers

Fascinatingly, the McPherson study (2014) also found that smokers were significantly less likely to sustain a third or fourth degree tear, you would imagine this to be because of the growth restriction more common in foetuses of women who smoke in pregnancy however the weight of babies (in this study at least) born to women who suffered these tears was not shown to be a risk factor in its own right. Definitely not a reason to suggest women at risk take up smoking, but interesting nonetheless!

Summary and Recommendations

In summary, third and fourth degree tears present a significant risk to long term morbidity and great care should be taken to identify them when they occur. There are a number of risk factors including ethnicity, primiparity, prolonged second stage, shoulder dystocia, instrumental delivery and, perhaps controversially given the apparent cloak of silence surrounding it, water birth. Midwives role in reducing the risk centres around antenatal education and the facilitation of informed decision making. Then continuous intrapartum support to promote a physiological labour as well as specifically applying warm compresses to the perineum at birth. A wider recommendation would be the training and recruitment of more midwives to ensure that continuous support is available at point of need and then a continuous program of training in the identification of third and fourth degree tears.

References

Albers, L. 1996. Factors related to perineal trauma in childbirth.  J Nurse Midwifery. 1996 Jul-Aug;41(4):269-76. https://www.ncbi.nlm.nih.gov/pubmed/8828312  [Accessed online 12/03/2017]
Clement, S. and B. Reed (1999). “To stitch or not to stitch? A long-term follow-up study of women with unsutured perineal tears.” Practising Midwife 2(4): 20
Dahlen HG, Homer CSE, Cooke M, et al. 2007. Perineal outcomes and maternal comfort related to the application of perineal warm packs in the second stage of labor: a randomized controlled trial. Birth 34(4): 282-290. Cited in RCM Evidence based guidelines for care in labour; Care of the Perineum https://www.rcm.org.uk/sites/default/files/Care%20of%20the%20Perineum.pdf [Accessed online 12/03/2017]
Ferando RJ, Sultan AH, Radley S, Jones PW, Johanson RE. 2002. Management of obstetric anal sphincter injury: a systematic review and national practice survey. BMC Health Services Research 2: 9. Cited in https://www.rcm.org.uk/news-views-and-analysis/analysis/perineal-trauma-reducing-associated-postnatal-maternal-morbidity  [Accessed Online 01/03/17)]
Glazener, C. 1997. Sexual function after childbirth: women’s experience, persistent morbidity and lack of professional  recognition. British Journal of Obstetrics and Gynaecology 104: 330-5 [Accessed Online 01/03/17] https://www.ncbi.nlm.nih.gov/pubmed/9091011
Hastings-Tolsma, M. et al. 2007. Gdetting through birth in one piece: Protecting the perineum. MCN Am J Matern Child Nurs. 2007 May-Jun;32(3):158-64. [Accessed online 12/03/2017] https://www.ncbi.nlm.nih.gov/pubmed/17479052
Kettle C, Johanson RB. 2000. RCOG green top guidelines: materials and methods used in perineal repair. RCOG: London
Lee, J & J Cresswell. 2013. Water Births: A Possible Risk Factor For Obstetric Anal Sphincter Injury. http://fn.bmj.com/content/98/Suppl_1/A78.4 [Accessed online 12/03/2017]
Mcpherson, K et al. 2014. Can the risk of obstetric anal sphincter injuries (OASIs) be predicted using a risk-scoring system? BMC Res Notes. 2014; 7: 471. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119183/ [Accessed Online 12/03/2017]
Royal College of Obstetricians and Gynaecologists (RCOG) 2015. A third or further degree tear during birth: Information for you. [Accessed online 01/03/17] https://www.rcog.org.uk/globalassets/documents/patients/patient-information-leaflets/pregnancy/pi-third–or-fourth-degree-tear-during-birth.pdf

Comments

Popular posts from this blog

Boobtastic Media Storm

My Baby Breastfeeds Too Often

Baby Led First Foods Update