Hypothesis / aims of study
Pregnancy and birth are the main risk factors for urinary incontinence (UI) in women. Prevalence of UI following birth ranges from around 30% in the first 3 months to up to 47% at some time in the first 12 months postpartum (1). Between two-thirds and three-quarters of women who have postpartum UI still experience leakage 12 years after giving birth (2).
A Cochrane review found moderate-quality evidence (3) that antenatal pelvic floor muscle exercises (PFME) reduce UI up to 6 months postpartum. However, most interventions were delivered by specialist health professionals, mainly physiotherapists. In the UK all women are seen throughout pregnancy by a midwife and it was considered important to investigate if midwives could incorporate a suitable PFME intervention into routine antenatal care; and if this might result in women undertaking enough PFME to prevent postnatal UI. However, most UK midwives are not trained to support women in undertaking antenatal PFME. As part of this overall research programme a comprehensive training package for midwives and resources for pregnant women to support teaching of PFME within antenatal care was developed and evaluated in a feasibility and pilot cluster randomised controlled trial (RCT). The quantitative results of this trial are reported here.
Study design, materials and methods
The feasibility and pilot cluster RCT allocated community midwife teams from two NHS hospitals to either intervention or control teams. The midwives in teams allocated to the intervention received the PFME training from research midwives employed on the trial. Midwives in control teams continued with standard antenatal care which may or may not included advice on PFME according to the midwife’s usual practice.
Due to ongoing NHS social distancing policies in response to COVID-19, the intervention comprised online training sessions of approximately two hours. Content included pelvic floor muscle anatomy and physiology, vignettes and role-play on how to teach and discuss importance of a healthy pelvic floor, a video of how to teach women about PFME, how to assess and teach correct muscle contraction and when to screen and refer for more serious incontinence problems. Following training the community midwives incorporated the PFME advice and support throughout pregnancy to all women in their care. They introduced the topic of pelvic floor health at the antenatal ‘booking’ appointment or as early as possible after this. Women were given an intervention resource pack, including a leaflet with PFME information, a link to videos, recommended Apps to support PFME, and trial logo stickers to use as reminders. The midwives were expected to ask women at all subsequent antenatal appointments about PFME progress and any problems with PFME or incontinence with referral if needed. A midwife ‘champion’ from each community team was offered further training by the researchers to support colleagues in their teams as needed.
The intervention training period was January-March 2021. Women who gave birth during December 2021 were sampled to assess quantitative trial outcomes as all their antenatal care would have occurred during the trial. The women were sent a postal questionnaire at 10-12 weeks postpartum and a reminder if no questionnaire was returned after two weeks. Questionnaires included trial specific questions (content of midwife care re PFME advice offered, if women performed PFME) and validated measures including the ICIQ-UI SF. The questionnaires were sent by the research midwives employed by the two NHS hospitals included in the trial. Questionnaire data were linked to women’s maternal, obstetric and infant data, obtained (with consent when questionnaire was returned) from hospital records by hospital research midwives. Similar anonymised data on all women who delivered during the same period but did not return a questionnaire were obtained for comparison.
As a feasibility and pilot cluster trial, no formal sample size calculation was performed to estimate a pre-specified effect size. Sample size was based on the number and size of clusters needed to estimate the return rate of questionnaires (across trial arms) to an acceptable level of precision.
Results
All 17 midwifery team clusters in the two participating NHS hospitals were randomized, 8 to intervention and 9 to control, comprising 186 midwives, 95 in intervention and 91 in control teams. Number of years working as a midwife were similar in intervention and control clusters (mean 11.3 and 13 years respectively). Most midwives in both groups were band 6 level.
Of 998 women sent a postpartum postal questionnaire, 175 (17.5%) were returned: 88/531 (16.6%) women in intervention clusters, and 87/467 (18.6%) in control clusters. Women’s demographic (Table 1), obstetric, and infant characteristics were similar across both trial arms. Women were asked in their questionnaire if they had leakage of urine at the start of pregnancy as this is a risk factor for postpartum UI; the proportion who reported pre-pregnancy UI was similar across trial arms.
Comparison of maternal, obstetric and infant characteristics among those who did and did not return questionnaires were similar except for some suggestion of differences in the proportions of women from ethnic minority groups (fewer among those who returned questionnaires) and parity (fewer multiparous women among those who returned questionnaire).
Based on women’s responses to the questionnaire, 65% (95%CI 56.9%-72.4%) of those in intervention clusters said their midwife explained how to do PFME, compared to 38% (95%CI 24.6%-51.2%) of women in control clusters. This was the pre-specified main assessment of whether the intervention had been delivered as planned. The pre-specified assessment of women’s adherence to PFME was whether they reported having undertaken PFME a few times a week or more, considered to be frequent enough to be likely to reduce UI symptoms; 50% (95%CI 24.1%-77.1%) of women in intervention clusters compared to 38% (95%CI 12.4%-67.1%) in control clusters reported this level of adherence to PFME during pregnancy. UI was ascertained using ICIQ-UI SF and 44% (95%CI 32.0%-56.1%) of women in intervention clusters reported UI compared to 54% (95%CI 42.2%-65.8%) in control clusters.
Interpretation of results
The quantitative results of this feasibility cluster RCT indicate that training and resourcing midwives appropriately to teach and support women to undertake pelvic floor muscle exercises in pregnancy is feasible, could improve women’s PFME adherence and might reduce postpartum urinary incontinence. Although the main limitation was a low questionnaire return, the birth characteristics of the women were similar across trial arms and similar to those who did not return a questionnaire. Taken together with the trial process outcomes (separately presented).