Study design, materials and methods
A prospective randomized controlled study had been conducted from May 2016 to December 2017 which was approved by the Institutional Review Board of the University Hospital (CSMUH No.CS 15016). Eighty-two primiparous women who had a spontaneous vaginal delivery with a non-extended second-degree perineal laceration were recruited into this study and were assigned into two groups which were either underwent electromyography biofeedback assisted or verbal instructed PFME (42 vs. 40) at the first week and repeated at the fourth week postpartum. These women were asked to perform PFME at home according to the study protocol until the sixth week postpartum. The PFME protocol was as follows: 1) fast contractions lasting for 2 seconds, rest for 4 seconds, with 20-30 repetitions 2) rest for 5 minutes and then begin the sustained contractions lasting for 5 seconds, rest for 10 seconds, with 5-10 repetitions . After finishing the 1st set of both contractions, rest for 10 minutes then repeat the 2nd set of fast and sustained contractions. The EMG-BF (Myomed134, Enraf-Nonius) assited PFMT included two surface electrodes ( Adhesive electrodes -EN-Trode Ø 2, 2 cm, 2 mm) attached at the 2 o’clock and 10 o’clock position around the anus. The women looked at the monitor screen to learn and adjust to the correct pelvic floor muscle contraction and relaxation. The women were asked if there was any discomfort or perineal wound pain after each training session. Then the women were given written instructions to perform the same exercise protocol three times (or at least twice) a day at home until 6 weeks postpartum. During the home training period, the same physiotherapist monitored the participants’ exercise adherence via a telephone interview once a week. The Pelvic organ Prolapse Urinary Incontinence Sexual Questionnaire (PISQ-12) and Urinary Distress Inventory short form questionnaire (UDI-6) were used for evaluating sexual function and impact of LUTS at immediate, six weeks, three months and six months postpartum. The validated PISQ-12 is a self-administered questionnaire containing 12 items divided into three domains: behavioral-emotional (items 1-4), physical ( items 5-9) and partner-related ( items 10-12). It uses a 5-point Likert scale ranging from 0 to 4, with 48 being the maximum score; higher scores indicate better female sexual function . UDI-6 is a scoring system that indicates overall lower urinary tract symptoms and severity . Pelvic floor muscle strength was assessed at the sixth week postpartum including baseline and maximal voluntary contraction. Only data derived from those women who completed all questionnaires at 6 months postpartum were used for analyzing.
Totally, forty-five women were successfully followed up until 6 months postpartum and completed all the questionnaires. There were no significant difference between the basic characteristics of women who performed electromyography biofeedback assisted PFME (23/42) and verbal PFME (22/40) (Table 1).
There were no difference in baseline muscle strength between women who performed electromyography biofeedback assisted PFME and verbal PFME (3.2± 3.0 vs 3.8±4.0; P= 0.84) at 6 weeks postpartum. The maximum voluntary contraction was stronger in women who performed electromyography biofeedback assisted PFME (11.9±6.2 vs. 8.7 ±4.4; p=0.173).
The total PISQ-12 scores were no significant difference between two groups at 6 weeks, 3 months and 6 months postpartum (Table 2).
Women who performed electromyography biofeedback assisted PFME had a higher score at the sixth week (10.6±1.2 vs 9.4±2.1, p=0.04) and the third months (11.0±1.2 vs 9.7±1.8, p=0.01) postpartum but no significant difference between these two groups at 6 months postpartum. Furthermore, the score related to change of orgasm intensity compared between past and present was significantly higher in the women who performed electromyography biofeedback assisted PFME at the sixth week (3.0±1.1 vs. 2.0±1.4, p=0.02) and third month (3.0±1.2 vs. 2.0±1.5, p=0.02) postpartum after analysis of all the individual questions on the PISQ -12 questionnaire. Total UDI-6 score steadily decreased in the women who performed electromyography biofeedback assisted PFME over time. However, all postpartum LUTS gradually improved over time in both groups without a statistically significant difference.
Interpretation of results
Our results showed that there were no statistically significant differences in overall sexual function and remission of LUTS between women who performed electromyography biofeedback assisted or verbal PFME and only orgasm intensity significantly improved in women who performed electromyography biofeedback assisted PFME at 6 weeks and 3 months. These inconclusive findings might be caused by lack of enough sample size to complete the six months follow-up in both groups.