Pelvic Floor Muscle Training (PFMT) in Treatment and Prevention of POP (POP Study)

Background for the study:

The incidences and prevalence of POP is difficult to determine, since many women do not seek medical advice and treatment for the condition. It has been estimated that half of women who have given birth lose some of the pelvic floor support, resulting in some degree of prolapse. Of these 10-20% will seek medical help. About 10% of all women will at one point in life undergo surgery for a prolapse condition. The incidence of POP requiring surgery after a hysterectomy is 3.6% per 1,000 women per year in the UK.

Treatment of POP can be conservative (PFMT), mechanical (use of a pessary) or surgical. A recently published Cochrane review concluded that there are no studies evaluating the effect of PFMT on POP. PFMT is without adverse effects, and theoretical knowledge of anatomy and function of the PFM provides a basis for trying strength training of the PFM both to prevent and to reverse POP.

In Norway Bø (1990, 1999) PhD, physiotherapist and professor at the Norwegian School of Sport Sciences (NSSS), has developed a training model for strengthening the PFM. The results from several randomised controlled trials of this program have shown high cure and improvement rates both in prevention and treatment of urinary incontinence.

Ultrasound and MR examinations have shown that after vaginal delivery the pelvic floor is situated in a lower position than in nullipara. In addition, the pelvic floor of stress urine incontinent (SUI) women is in a lower position than of continent women. DeLancey et al (2003) showed that women with POP generated 43% less maximum force and had more atrophy of the pelvic floor muscles than women without prolapse. One of the main theories explaining the effectiveness of PFMT on SUI includes factors that may change through strength training: increased cross-sectional area of the muscle (muscle volume), neurogen adaptation, imposed viscoelastic properties ("stiffness") of the connective tissue and altered location of the PFM at a higher level in the pelvic cavity. Morphological changes in relation to PFMT have not been examined in RCTs, but have shown a cure rate of 44-70% measured as < 2 gram leakage in various pad tests and significant increase in muscle strength after PFMT.

Several studies have shown that > 30% of women are unable to contract the PFM properly at the first consultation. Bump et al (1991) showed that 25% were pushing downwards instead of lifting up and in. Other common mistakes are to use muscle groups outside the pelvic area instead of the PFM. Instruction, feedback, close follow-up and high adherence are important factors if the strength training.

Objective:

The aim of the present study is to evaluate whether PFMT can reverse and prevent further development of POP. The project comprises a RCT (main study). In addition we will conduct a case-control study to investigate risk factors, such as muscle strength and joint flexibility in women with and without POP. The project description below will focus on the RCT. The same measurements will be used in the case-control study, and women participating in the RCT will be cases of the case-control study.

Method, design:

The main study is a prospective randomised trial. Women with POP will be referred by selected community gynaecologists working in Oslo and Akershus. Those who express an interest in participating in the project will be referred to physiotherapist and manual therapist Ingeborg Hoff Brækken, who is the project manager. The women will participate in a structured interview; complete a questionnaire about symptoms and quality of life and undergo a clinical examination at. Gynaecologist Majida at Akershus university hospital will conduct the ultrasound examination. The women will be stratified by the stage of prolapse after the pelvic floor prolapse quantifying (POPQ). They will then be randomised into two groups; PFMT or control. Brækken will train the intervention group at Hans \& Olaf Fysioterapi A/S. The gynaecologist will be blinded for group allocation. After 6 months all women from both groups will be referred to the physiotherapist where they will complete the same questionnaire about symptoms and quality of life and measure PFM strength. The gynaecologist will then conduct the same ultrasound examination and POPQ.

Drop-out routines:

The "intention to treat" principle will be followed. Moreover, a per-protocol analysis will be carried out in those who have completed ≥ 80% of the recommended training regimen.

Protocol for PFMT:

1. Pre-contraction (the "knack"). All women will be taught how to contract the PFM before, during and after increases in abdominal pressure (coughing, sneezing, heavy lifting)
2. Home training. The intervention group will be asked to perform 3 sets of 8-12 near maximum contractions per day in different positions with the legs abducted. All women will receive a booklet and a DVD showing the exercise program. Adherence will be noted in a diary
3. Training and follow-up with a physiotherapist. The women visit the physiotherapist for training with vaginal pressure biofeedback once a week for 3 months. For the next 3 months they train once every second week with the physiotherapist (total of 18 times). Muscle strength is registered at each visit.

The control group receives no treatment. After the project period they will be referred to a physiotherapist if they so wish.

Case-control study:

In parallel with the training intervention, 50 female controls without POP will be referred from the same gynaecologists. In this case-control study only women with stage 0 on POPQ will be included in the control group. They will be examined in the same way as the main study group by the physiotherapist and gynaecologist. PFM strength and clinical tests for "benign hypermobility joint syndrome" will be conducted. They also complete the same forms as in the RCT.

Statistical analysis:

We use SPSS version 11 for data analysis with relevant statistical methods to compare the groups. Results of continuous variables will be given as an average of 95% CI. Results will be given as numbers needed to treat (NNT). The level of significance will be set at < 5%. Professor of statistics, Ingar Holme PhD, NSSS, is advising the project.

Ethics

Names and personal identity numbers will not be registered. All data will be stored in a locked and fireproof cabinet. Data is filed in the same way as all the project data at Norwegian Social Sciences Data Services (NSD) in Bergen. The project complies with the Helsinki declaration in requiring all participants to give their written informed consent. The project has been approved by the Southern Regional Health Authority's committee on medical ethics.