EPI-NO® is a device that aims to stretch perineal structures gradually and slowly in the prenatal period to prevent a rapid 
traumatic laceration during childbirth. However, the benefits of this device remain controversial, since there is data regarding inefficacy when not used under specialized supervision (1,2,3). We hypothesized that supervised use of EPI-NO® by a physiotherapist, may avoid inadequate device manipulation and positioning bias and result in adequate muscle stretching during vaginal delivery (VD).  
This study aimed to assess the efficacy of early and supervised use of EPI-NO® device in the prevention of perineal trauma and urinary incontinencie (UI) 6 months after delivery in primigravid women.

A non-randomized clinical trial was conducted in a low-risk maternity hospital. The study group (SG) comprised primigravid women aged 18–40 years between the 30th and 32nd gestational weeks who were attended and referred by the Health Units and underwent supervised use of EPI-NO®. 
The control group (CG) participants were recruited after delivery, through a screening of medical records and a face-to-face interview while they were still hospitalized. The recruiters were blinded to the birth outcomes before selection/invitation. Puerperal women were invited to participate in the study, which considered an evaluation 6 months after delivery. CG included low-risk pregnant women hospitalized for childbirth in the same maternity unit. Inclusion criteria were as follows: primigravid women with a single fetus, aged between 18 and 40 years, gave birth between 37 and 42 weeks without complications, who agreed to participate in the project, signed the consent form, and attended the evaluation. 
The exclusion criteria were: UI before pregnancy, hypertension, gestational diabetes, placenta previa, twin pregnancy, multiparity, previous perineal or VD, urinary infection, genital herpes, vaginal candidiasis, and any other diagnoses that could potentially put the pregnancy at risk. SG was evaluated before the intervention (between the 30th and 32nd week) and 6 months after delivery. Patients in the CG were evaluated at baseline and 6 months after delivery. Individual evaluations were performed for both groups by a blinded physiotherapist specialized in obstetrics based on medical history, physical examination, and ICIQ-SF questionnaire. 
Perineometer was used, and average of the three maximum contractions was used for the analysis. The ICIQ-UI SF was applied in both groups at baseline and 6 months after delivery in SG; and 6 months after delivery in CG. Pregnant women in the SG underwent 10 sessions (twice a week for 5 weeks) with the EPI-NO® device from the 34th gestational week onwards.  The protocol was developed by researchers based on literature and a physiotherapist with experience in urogynecology performed the interventions. All pregnant women (SG and CG) gave birth in the same hospital. 
Perineal lacerations were report and classified.

In the SG, 37 participants were analyzed, whereas 32 participants in the CG were eligible for analysis at 6 months after VD. There were no significant statistical differences between the groups concerning baseline characteristics  or the median Apgar scores in the first and fifth minute and duration of expulsion stage. 
Overall, 83.8% and 34.4% of patients experienced no or grade I perineal laceration in the SG and CG, respectively (p = 0.0001). Table 1 presents the detailed results regarding perineal lesions. CG had a 9.86% greater chance (odds ratio, 95% CI = 3.15–30.79) of presenting second- or third-degree perineal lacerations or undergoing an episiotomy. Multivariate logistic regression model included EPI-NO® use, expulsion stage duration, maternal obesity, and baby's size and weight. Only EPI-NO® use (odds ratio = 0.03) and duration of expulsion stage (odds ratio = 1.06) remained as protective factors in the multivariate model. SG had a 96.7% lower chance of a deep laceration than CG, while participants with a longer than average expulsion stage duration had a 1.06% higher chance of a deep laceration (Table 2).  
The mean maximum vaginal circumference (cm) of the EPI-NO® device reached by participants in the SG (25.98 ± 2.28) was also analyzed and compared based on the presence of a superficial trauma (intact perineum or presence of first-degree laceration; 
26.29 ± 2.22) and presence of a deep trauma (second- or third-degree perineal lacerations or episiotomy; 24.38 ± 2.00). No significant differences were observed between the two groups (p = 0.05). Mean circumference reached by each patient during the sessions was also recorded, and no significant difference (p = 0.53) was found after dividing them into superficial (22.40 ± 2.15) and deep lesions (21.80 ± 2.11). There were no adverse events or tolerability issues regarding the supervised use of EPI-NO® reported by the SG patients. 
At 6 months after delivery, only one (2.7%) participant in the SG and six (18.75%) in the CG reported the need to use a pad (p = 0.07). No UI was experienced by 21 (56.75%) participants in the SG and 17 (53.12%) in the CG; however, 14 (37.83%) in the SG and 11 (34.37%) in the CG reported stress UI  according to the ICIQ-SF. None of the participants in SG and one (3.12%) in CG complained of urgency UI, whereas two participants (5.40%) in SG and three (9.37%) in CG reported mixed UI. There were no differences between groups in regard to UI type (p = 0.65). Pad usage, continence status and ICIQ-SF 6 months after delivery are presented in table 3. Women in the SG had a significantly lower median ICIQ-UI SF postpartum than those in the CG (p=0.002). Additionally, the SG presented a significantly lower score in ICIQ-SR Q5 (QoL) than the CG (p = 0.0166). 
SG group had a maximum perineal strength, average strength and duration of pelvic floor contraction significantly higher than the CG group (table 5). A statistically significant (p = 0.0016) inverse correlation (−0.38) was observed between perineal 
strength and ICIQ-UI SF score in the SG.

The use of EPI-NO® was associated with a significantly higher maximum perineal strength, a significant lower median value of the 
ICIQ-UI SF, a better quality of life, according to the ICIQ-SF and less deep perineal trauma. Furthermore, the frequency of women with an intact perineum or spontaneous first-degree laceration only was significantly higher in the SG than in the CG. 
There is only scarce literature on the supervised use of EPI-NO® in preventing postpartum UI and/or trauma in primigravid women (references). EPI-NO® use under specialized guidance may be one of the reasons behind positive outcomes: user’s understanding of received guidance, positioning of the balloon in the vaginal introitus, understanding of the manipulation of the device, presence of contraction or relaxation of the pelvic floor, time of use, and gradual increase in circumference [1,2,3]. All these factors were better controlled by the presence of a professional. Thus, we hypothesized that the EPI-NO® would also be more effective if started in the same period as perineal massages, enhancing the purpose of its use, which includes smoothing the tissues and promoting gradual stretching with increased extensibility in the region.  
The main limitation of this study was the lack of randomization and the restricted number of patients.

Supervised use of the EPI-NO® from 34 weeks of gestation was associated with less deep trauma, a better quality of life, a significantly lower median ICIQ-UI SF, and a trend towards less use of pads 6 months after VD.

Shek KL, Chantarasorn V, Langer S, Phipps H, Dietz HP. Does the Epi-No Birth  Trainer reduce levator trauma? A randomised controlled trial. Int Urogynecol J.  2011 Dec;22(12):1521-8
Mendes NA, Mazzaia MC, & Zanetti MRD. Critical analysis on the use of Epi-No  in  pregnancy and delivery. ABCS Health Sciences. 2018, 43(2).
Kamisan Atan SKL, Langer S, et al. Does the EPI-NO® birth trainer prevent  vaginal birth-related pelvic floor trauma? A multicentre prospective randomised  controlled trial. BJOG. 2016;123(6):995–1003.