Obstetric perineal ruptures – risk of anal incontinence 12 months postpartum: a prospective cohort study

Gommesen D1, Nohr E1, Qvist N2, Rasch V1

Research Type

Clinical

Abstract Category

Anorectal / Bowel Dysfunction

Abstract 18
Urogynaecology 1 - Pelvic Organ Prolapse
Scientific Podium Short Oral Session 2
Wednesday 4th September 2019
10:22 - 10:30
Hall H2
Anal Incontinence Female Prospective Study Urgency, Fecal Pelvic Floor
1.Department of Gynaecology and Obstetrics, Odense University Hospital. Institute of Clinical Research, University of Southern Denmark, 2.Department of Gastroenterological Surgery, Odense University Hospital
Presenter
D

Ditte Gommesen

Links

Abstract

Hypothesis / aims of study
Anal incontinence after vaginal delivery is a major concern for many women. Anal incontinence is defined as the involuntary or uncontrolled loss of mucus, liquid or solid stool or the passage of gas (1). It is supposedly an underreported condition because of its stigmatizing role (2). It occurs in approximately 50% of women at long-term follow-up after anal sphincter ruptures. The prevalence of anal incontinence six months postpartum has been reported to be as high as 49% among primiparous women in general. Only about half the cases of anal incontinence after childbirth can be related to anal sphincter injuries and the remaining cases of anal incontinence must thus be related to other factors (3). However, the pathophysiological mechanisms of anal incontinence are still not fully understood and the condition remains an unsolved problem for many patients. The objective of this study was to examine the association between degree of perineal rupture and anal incontinence 12 months postpartum among primiparous women.
Study design, materials and methods
This study was a multi-center prospective cohort study conducted at four hospital units; two univer-sity hospitals and two general hospitals from July 2015 until January 2019.
A total of 574 primiparous women (193 with none/labia/1st degree ruptures, 192 with episiotomies/2nd degree ruptures, 189 with 3rd/4th degree ruptures) were included. Baseline data was ob-tained 2 weeks postpartum. Subjective symptoms of anal incontinence were evaluated 12 months postpartum by a web-based questionnaire (n=574) and a clinical examination of anal function using endoanal ultrasound scanning (n=499) and High Resolution anal manometry (n=482). Main outcome measurements were: Anal incontinence (St. Mark’s score >4), endoanal ultrasound find-ings (defect in internal and/or external anal sphincter muscles) and anal manometry findings (rest pressure, maximum squeeze pressure, maximum duration of squeeze).
Results
Women suffering from an anal sphincter rupture had higher risk of anal incontinence compared to women with ruptures of lower degree, adjusted Relative Risk (aRR) 2.85, 95% CI 1.36-5.98. The risk of anal incontinence increased with 8% per one unit increase in body mass index, aRR 1.08, 95% CI 1.03-1.14.  A rupture of degree 3c and 4 increased the risk of anal incontinence with aRR of 6.81 (95% CI 2.03-22.9) and aRR of 5.50 (95% CI 1.42-21.3), respectively. Patients with incontinence had a lower anal resting tone of 62.5 mmHg compared to 78.6 mmHg in women with no incontinence (p < 0.001).The values for maximum squeeze pressure in the two groups were 128.3 and 158.4 mmHg, respectively (p < 0.001).
Interpretation of results
Obese women are in higher risk of developing anal incontinence postpartum regardless degree of rupture compared to women of normal weight. Obesity is the most common health care problem in women of reproductive age. Maternal obesity has become highly prevalent worldwide and is a ma-jor concern in obstetrics. As a consequence, the number of adverse maternal outcomes must be expected to rise. Low anal pressure seems to indicate a defect in the external anal sphincter muscle or in the internal anal sphincter muscle , and as an ultrasound verified defect is associated with poorer outcome, it is important to identify the full extent of injury in women who sustain 3rd or 4th degree ruptures. Further, a particular attention to repair of defects in the internal anal sphincter muscle is needed. In this study, women who had sustained a grade 3c or 4 rupture had a poorer outcome compared to those who had sustained a grade 3a or 3b rupture or women with even smaller ruptures. It is therefore important to identify the full extent of injury at delivery, paying particular attention to repair of the internal anal sphincter muscle as a defect in the internal anal sphincter muscle is associated with increased risk of anal incontinence. We suggest that repairs should be performed in a theater under appropriate circumstances to optimize diagnosing and repair of the rupture.  Moreover, routine follow‐up after repair of 3rd and 4th degree ruptures is important in order to tackle any defecatory problems at an early stage.
The present study also found that neither instrumental delivery nor episiotomy had any influence on the risk of developing anal incontinence 12 months postpartum, and the results support the ongoing initiative among midwives and obstetricians to minimize perineal ruptures during childbirth and avoid anal sphincter ruptures when possible.
Concluding message
In conclusion, there is an increased risk of developing anal incontinence one year postpartum after anal sphincter ruptures especially if a defect in the internal anal sphincter muscle is present. Fo-cused training in identifying and repairing anal sphincter ruptures may also be warranted. Additionally, an added focus on BMI and preventing anal sphincter ruptures may be beneficial in reducing postpartum anal incontinence problems among women.
References
  1. Haylen BT, de Ridder D, Freeman RM, et al. An International Urogynecological Association (IUGA)/International Continence Society (ICS) joint report on the terminology for female pelvic floor dysfunction. Neurourology and urodynamics 2010;29(1):4-20. doi: 10.1002/nau.20798 [published Online First: 2009/11/27]
  2. Damon H, Guye O, Seigneurin A, et al. Prevalence of anal incontinence in adults and impact on quality-of-life. Gastroenterologie clinique et biologique 2006;30(1):37-43. [published Online First: 2006/03/04]
  3. Abramowitz L, Sobhani I, Ganansia R, et al. Are sphincter defects the cause of anal incontinence after vaginal delivery? Results of a prospective study. Diseases of the colon and rectum 2000;43(5):590-6; discussion 96-8. [published Online First: 2000/05/29]
Disclosures
<span class="text-strong">Funding</span> The study was funded by Odense University Hospitals Research Foundation, The Region of Southern Denmark, University of Southern Denmark, the Department of Gynecology and Obstetrics, Odense University Hospital, The A.P. Moeller Foundation for the Advancement of Medical Science (grant no.13-93), and The Danish Association of Midwives. <span class="text-strong">Clinical Trial</span> No <span class="text-strong">Subjects</span> Human <span class="text-strong">Ethics Committee</span> The study was approved by the Scientific Ethics Committee for the Region of Southern Denmark (S-20120213, 14.5.2013) and by the Danish Data Protection Agency (ID-2008-58-0035, 14.1.2015). <span class="text-strong">Helsinki</span> Yes <span class="text-strong">Informed Consent</span> Yes