Title: Preventing pelvic floor dysfunction: does childbirth impair vaginal sensation and how does this relate to pelvic floor dysfunction?
Funder: Department of Health and Social Care

Abstract: Background Pelvic floor dysfunction (pelvic organ prolapse, urinary, bowel and sexual dysfunction), or PFD, impairs the quality of life of over one third of women. It can lead to debilitating symptoms leading to social isolation, relationship breakdown, employment limitations and loss of independence. Despite this, and the rising economic cost of treatment, it remains a neglected area of women's health and an important public health issue. The pelvic floor is supplied by the pudendal nerve which consists of motor and sensory fibres. Research has demonstrated that vaginal birth damages pudendal nerve motor fibres and is a major factor in the development of PFD. It follows that injury to sensory fibres occurs at the same time, however, this has never been studied. Sensation is a subjective perception, and testing is more difficult than testing motor function. The use of a validated protocol can provide a reproducible assessment of pelvic sensory function, termed quantitative-sensory testing (QST). Aims 1) Determine whether mode of delivery affects pelvic floor sensation 2) Establish if changes in sensation following childbirth correlate with symptoms of pelvic floor dysfunction (PFD) 3) Identify modifiable obstetric factors which influence pelvic sensation 4) Evaluate whether changes in pelvic anatomy are associated with sensory deficit 5) Validate stretch as a modality for quantitative sensory testing (QST) of the vagina and at the introitus 6) Compare vibrotactile equipment with quantitative sensory testing (QST) principles to a hand-held vibration device, Vibratip Plan of Investigation A prospective non-interventional cohort study of 147 primiparous women will be assessed at 36 weeks gestation, ten weeks and six months postnatally. Sensory assessment will involve vibration testing of the vagina and clitoris and stretch sensation of vagina and introitus following QST principles. The test for vaginal stretch sensation is a new procedure and so will be validated in 20 non-pregnant controls beforehand. At each visit women will be asked to complete a validated symptom-specific PFD questionnaire (ePAQ). The ePAQ system provides numerical values for each symptom domain of PFD which will then be compared to sensory thresholds for vibration and stretch. Delivery details including mode of delivery and modifiable obstetric factors will be recorded and related to sensory thresholds. A vaginal examination using the Pelvic-Organ Prolapse Quantification system (POP-Q) will be performed. Although the vibrotactile equipment is a sensitive robust tool and the gold-standard in QST, the machine itself is not practical to use in a clinical setting. Therefore a simple hand-held vibration device (Vibratip) which has previously been validated for peripheral neuropathy will be assessed for use in female genital testing. Potential Benefits to Patients Improve understanding of the pathophysiology of PFD If sensation is an important part of the pathophysiology, treatment will need to be adjusted to include this Identify risk factors in obstetric practice to enable women and obstetricians to make informed choices. Potential Benefits to the NHS Many women with PFD are chronic attendees and users of healthcare resources. Many current treatments also have high failure and recurrence rates. If PFD can be better treated this will reduce the burden on NHS resources. If it can be prevented the reduction in cost to the NHS will be even greater.

Lay abstract: Background Childbirth injures the pelvic floor muscles and this can cause prolapse, incontinence of urine and faeces and sexual problems. As a group these symptoms are called pelvic floor dysfunction. Pelvic floor dysfunction affects the quality of life in over one third of women in the UK. The combination of rising healthcare costs, more women seeking treatment and an ageing population mean the cost of treating pelvic floor dysfunction has more than doubled over last decade.(1) The limited understanding of the causes of PFD means that management options have not developed and prevention cannot be implemented without understanding the causes. This fits in with the Department of Health's public health framework for 2013-16, which describes 'reduced numbers of people living with preventable ill-health' as its key objective.(2) PFD remains a neglected area of women's health and an important public health issue. Research has shown that one of the major causes of PFD is injury during childbirth to the nerves which supply the pelvic floor muscles. The pelvis also contains nerves which supply sensation which are probably also damaged during childbirth, but so far only motor nerves have been studied in detail. It is likely that sensation as well as motor function plays an important role in normal urinary, bowel and sexual function. Studies have shown that one of the major causes of pelvic floor dysfunction is injury during childbirth to the nerves which supply the pelvic floor muscles. However, the pelvis also contains nerves which provide sensation. It is likely that sensory nerves are also damaged during childbirth, but so far only motor nerves have been studied in detail. As the motor nerve injury appears to result from childbirth, it follows that childbirth is also responsible for the sensory injury. Aims of the Research To find out whether vaginal delivery or caesarean section during childbirth affects sensation in the pelvis To link sensory changes following childbirth with symptoms of PFD To identify childbirth factors which might influence pelvic sensation and could be modified To test whether changes in anatomy are associated with sensory problems To validate a new test for sensation of stretch in the vagina and at the opening to the vagina To validate a hand-held vibration device for diagnosing sensory problems in women in the clinic Methods Women will be tested at 28 to 38 weeks pregnant, eight to 12 weeks and six months after delivery. At each of these visits, sensation will be tested using first awareness of vibration inside the vagina and at the clitoris, and sensation of stretch inside the vagina and at the entrance to the vagina. Sensation of vaginal stretch is a new test and so will be validated on 20 non-pregnant controls in the gynaecology clinic to determine normal values beforehand. At each visit, the position of the pelvic organs (POP-Q) will be measured and women will be asked to complete an electronic questionnaire specifically designed for symptoms of PFD. Delivery details will also be collected. The hand-held vibration device, Vibratip, was designed to test for peripheral nerve problems in the general medical clinic. In a group of 20 non-pregnant patients attending the Gynaecology clinic, sensory vibration testing will be performed using the gold-standard of Quantitative Sensory Testing compared to Vibratip. Patient and Public Involvement Patients and the public have been involved in the study from the beginning whether as part of the pilot study to test acceptability to women, review of patient leaflets and recruitment planning by women in the antenatal clinic or fine-tuning of the protocol and patient leaflets via the Materno-Fetal Health user group. Dissemination to the Academic Community I will publish in open-access journals and present findings at both national and international meetings. Dissemination to the Wider Public I will actively contribute to research road-shows via the host trust, the Greater Manchester Comprehensive Local Research Network for Reproductive Health and Childbirth Specialty Group, and the Manchester Academy for Healthcare Scientist Partnership. I will share findings with participants and the public through information leaflets, trust and university webpages and newsletters. References 1. Sung VW, Washington B, Raker C a. Costs of ambulatory care related to female pelvic floor disorders in the United States. Am J Obstet Gynecol. Elsevier Inc.; 2010 May;202(5):483.e14. 2. Coote A. Prevention Rather Than Cure: Making the case for choosing health (summary). 2004 p. 110.

Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: REPRODUCTIVE HEALTH AND CHILDBIRTH;RENAL AND UROGENITAL