DOI: https://doi.org/10.21203/rs.3.rs-1678303/v1
Background: Female pelvic floor disorders (PFD) include various clinical conditions, such as urinary and fecal incontinence and pelvic organ prolapse. PFD assessment has been facilitated by developing disease-specific questionnaires, such as the Pelvic Floor Distress Inventory-20 (PFDI-20). We aimed to investigate the prevalence of PFD in Japanese women after delivery and the association of PFD with epidural anesthesia.
Methods: This retrospective study included women who gave birth at our institution. The PFDI-20 questionnaire (validated in Japanese) was used to evaluate PFD symptoms 6–15 months postpartum.
Results: Of 212 postpartum women, 156 (73.6%) manifested PFD symptoms. The most prevalent PFD symptom was urinary distress in 114 (53.8%) women, wherein 79 (37.3%) women experienced urine leakage related to increased abdominal pressure.
Conclusion: A comparison of the epidural and non-epidural groups regarding the association between PFD and delivery mode revealed a higher disease burden score by 8.67 points in the epidural group. Therefore, correct diagnosis of women along with appropriate and regular follow-up until improvement of their symptoms would be significant. Healthcare workers should, therefore, inform pregnant women whether to choose vaginal delivery with or without anesthesia. To the best of our knowledge, our study is the first to investigate whole postpartum PFD in Japan.
Trial registration: Retrospectively registered.
Female pelvic floor disorders (PFD) include various clinical conditions, such as urinary incontinence, fecal incontinence, and pelvic organ prolapse (POP). PFD assessment has been facilitated by developing a disease-specific questionnaire, such as the Pelvic Floor Distress Inventory-20 (PFDI-20). The PFDI-20 is a 20-item questionnaire divided into 3 scale scores, evaluating POP distress (POPDI), colorectal anal distress (CRADI), and urinary distress (UDI).1
Pregnancy and labor are known risk factors for PFD.1 Among 196 Australian women, PFD was prevalent at 6 months postpartum in 97% according to PFDI-20.2 In a study conducted in Israel, 117 women were investigated at late pregnancy and puerperium. Their PFD assessment at 3 months postpartum showed POPDI in 12.8%, CRADI in 20.7%, and UDI in 15.8% women. Mixed trends of spontaneous recovery following childbirth have been reported.3
Anim-Somuah et al. have shown that epidural anesthesia is related to prolonged second stage of labor.4 Vaginal delivery with epidural anesthesia is associated with an increase in instrumental deliveries.5 Moreover, prolonged second stage of labor and forceps delivery may harm the pelvic floor muscles; thus, it may cause PFD in postpartum women.6 7 Epidural anesthesia is associated with urinary incontinence after delivery; however, it is not associated with prevalence of the disease at 3 and 12 months postpartum.8 Therefore, the hypothesis that epidural anesthesia affects pelvic floor function is reasonable. Contrastingly, another study has proposed that epidural anesthesia may relax the pelvic floor muscles and reduce indirect or direct trauma to the pelvic floor or prevent the development of symptoms related to pelvic floor trauma.9 Therefore, the association of risk for PFD with labor using epidural anesthesia is controversial. Thus, data is analyzed to reveal the association between the mode of delivery and PFD prevalence.
However, few studies have reported the association of PFD prevalence with epidural anesthesia in postpartum Japanese women. Therefore, we conducted this study to investigate it. This study aimed to investigate PFD prevalence in Japanese women at 6–15 months after delivery and the association between PFD occurrence and epidural anesthesia
We conducted a retrospective cohort study of women who gave birth between July 2018 and May 2019 at the Kameda Medical Center, Chiba Prefecture, Japan. An average of 600 deliveries is managed at our medical center annually. This study received the institutional ethical review board approval (approval ID, 19–052).
All applicants were informed and enrolled by mail, which included the informed consent paper. Hence, informed consent was received from all participants online before initiation of the study.
PFD was evaluated using the PFDI-20 questionnaire. The PFDI-20 consists of 20 items of condition-specific measures of pelvic symptoms. It has three subscales: Pelvic Organ Prolapse Distress Inventory with six items (POPDI-6), Colorectal-Anal Distress Inventory with eight items (CRADI-8), and Urinary Distress Inventory with six items (UDI-6).
Each question relates to the presence of an individual symptom. If the symptom is present, the responder scores it on a 4-point scale to indicate the extent of botheration; score 1 is not at all, and 4 is quite a bit.
POPDI-6, CRADI-8, and UDI-6 are each scored similarly. First, subscale scores for each scale are obtained by taking the mean value of all items answered within each subscale. These subscale scores are determined by multiplying each scale’s mean score by 25, which gives each subscale score a range of 0–100. Therefore, the total scale score is calculated by summing the subscale scores (a range of 0–300). A high score indicates more symptoms and higher levels of inconvenience by the symptoms. The questionnaire was based on the validated Japanese language version of the Pelvic Floor Distress Inventory-20 (PFDI-20).10 The questionnaire was put into a web form without any modification from the original form.
Participants were sent a questionnaire along with an explanatory document about PFDI-20, 6–15 months after delivery. The inclusion criteria for the study were as follows: non-preterm delivery, single pregnancies, and fluency in Japanese. The exclusion criteria for the study were as follows: women who either did not respond or responded incompletely to the questionnaire. In this study, no sample size calculation was performed a priori, and all available pregnant women were included during the study period.
We divided all women into the following groups: C-section, epidural (vaginal delivery with epidural anesthesia), and non-epidural (without epidural anesthesia).
The PFDI-20 questionnaire was answered at 6–15 months postpartum, reflecting the state during that period. A “yes” on the questionnaire represented a positive result, indicating the occurrence of PFD. Study IDs were assigned to each woman, and their medical information was obtained from the medical records.
We obtained age, parity, maternal body weight before the pregnancy, mode of delivery, and the result of delivery mode. Continuous variables with normal distribution were presented as mean, median values. We compared the maternal, fetal, and neonatal characteristics and PFDI-20 (POPDI, CRADI, and UDI) in each group. Continuous variables were compared using the t-test and categorical variables using the Chi-square test. A linear regression model for PFDI-20 (POPDI, CRADI, and UDI) was constructed, adjusting confounding factors (age, parity, and pre-pregnancy body weight). All confounding factors were referred to from the findings of previous study. The causal directed acyclic graphs (DAGs) was used to identify the potential interplay among variables.11 The supplementary figure shows our DAGs (Supplemental Data 1).
It is said that maternal age and pre-pregnancy body weight influence mode of delivery due to maternal obstetrical complications.12 13 Moreover, previous delivery mode affects the choice of delivery mode in future pregnancies; for example, the rate of vaginal birth after cesarean seemed to be reduced by 10–30% approximately in Japan.14 Additionally, these factors influence the PFD;15 therefore, we consider these factors as confounding factors. Statistical significance was defined as P < 0.05, and all statistical analysis was conducted by R version 3.6.3 22/07/2011 23:54:00 (R Foundation for Statistical Computing, Vienna, Austria).
We assumed that any missing data was missing completely at random; hence, we conducted all analyses using the available data.
A the total 336 women included in the study, 313 women met the inclusion criteria. However, a total of 101 women were excluded from the study due to no response or incomplete responses. Finally, 212 postpartum women were analyzed (Fig. 1).
Maternal, fetal, and neonatal characteristics (Table 1) revealed that the mode of delivery included emergency cesarean section in 14 (6.6%), elective cesarean section in 30 (14.2%), vaginal delivery with epidural anesthesia in 21 (9.9%), and vaginal delivery without epidural anesthesia in 147 (69.3%) women.
| Characteristics | n (%) | Cesarean section | Vaginal delivery with epidural anesthesia | Vaginal delivery without epidural anesthesia | p-value |
|---|---|---|---|---|---|
| Overall n = 212(%) | n = 44 | n = 21 | n = 147 | ||
| Age (mean (SD)) | 33.00 (4.73) | 34.59 (4.07) | 32.52 (4.53) | 32.60 (4.87) | 0.043 |
| Para (mean (SD)) | 0.68 (0.81) | 1.05 (0.94) | 0.57 (0.75) | 0.59 (0.76) | 0.004 |
| Pre-pregnancy body weight (mean (SD)) | 49.49 (16.79) | 46.19 (18.44) | 44.27 (22.66) | 51.23 (15.06) | 0.07 |
| Mode of delivery (%) | < 0.001 | ||||
| Emergency cesarean section | 14 (6.6) | 14 (6.6) | - | - | |
| Elective cesarean section | 30 (14.2) | 30 (14.2) | - | - | |
| Outcome of delivery (%) | < 0.001 | ||||
| Natural | 133 (62.7) | - | 11 (52.4) | 122 (83.0) | |
| Instrumental | 35 (16.5) | - | 10 (47.6) | 25 (17.0) | |
| Cesarean section | 44 (20.8) | 44 (100.0) | - | - | |
| Perineal laceration (%) | < 0.001 | ||||
| None | 99 (46.7) | 44 (100.0) | 2 (9.5) | 53 (36.1) | |
| 1st | 11 (5.2) | - | - | 11 (7.5) | |
| 2nd | 98 (46.2) | - | 19 (90.5) | 79 (53.7) | |
| 3rd | 4 (1.9) | - | - | 4 (2.7) | |
| Neonatal weight (mean (SD)) | 2988.87 (364.89) | 2949.82 (427.61) | 3027.14 (346.34) | 2995.09 (348.47) | 0.68 |
| aSD, standard deviation | |||||
The outcomes of delivery were spontaneous for 133 (62.7%), instrumental for 35 (16.5%), and cesarean section for 44 (20.8%) women. The degree of perineal laceration included none for 99 (46.7%), 1st for 11 (5.2%), 2nd for 98 (46.2%), and 3rd for 4 (1.9%) women.
Among all 212 postpartum women, a total of 156 (73.6%) women manifested PFD symptoms, breaking down into three groups, 59 had POPDI (27.8%), 111 had CRADI (52.4%), and 114 had UDI (53.8%). The most prevalent PFD symptom was UDI in 114 (53.8%) women, wherein 79 (37.3%) women experienced urine leakage related to increased abdominal pressure.
Moreover, the prevalence of PFD was statistically different (p = 0.037) in all groups and the readings were as follows: cesarean section, 27 (61.4%); epidural, 19 (90.5%); and non-epidural group, 110 (74.8%) (Table 2).
| PFDI | Cesarean section | Vaginal delivery with epidural anesthesia | Vaginal delivery without epidural anesthesia | p value |
|---|---|---|---|---|
| Overall (n = 212) | n = 44 | n = 21 (%) | n = 147 (%) | |
| PFDI-20 | 27 (61.4) | 19 (90.5) | 110 (74.8) | 0.037 |
| POPDI | 10 (22.7) | 8 (38.1) | 41 (27.9) | 0.433 |
| CRADI | 18 (40.9) | 15 (71.4) | 78 (53.1) | 0.067 |
| UDI | 19 (43.2) | 14 (66.7) | 81 (55.1) | 0.174 |
| aPFDI-20, Pelvic Floor Distress Inventory-20; POPDI, pelvic floor disorders distress; CRADI, colorectal anal distress; UDI, urinary distress | ||||
Multivariable regression for pelvic floor symptom burden score showed the following results: the epidural group had a 8.67-point higher symptom burden score (estimate, 8.67 (0.03–17.3)), and the cesarean section group had − 7.61 points (estimate, -7.61 (-14.2 – -1.03)), as compared to the non-epidural group, regarding the association between PFD and delivery mode (Table 3).
| PFDI-20 | POPDI | CRADI | UDI | |||||
|---|---|---|---|---|---|---|---|---|
| Coefficient | 95%CI | Coefficient | 95%CI | Coefficient | 95%CI | Coefficient | 95%CI | |
| Age | 0.42 | -0.13 ~ 0.98 | 0.13 | -0.080 ~ 0.33 | 0.14 | -0.096 ~ 0.37 | 0.16 | -0.15 ~ 0.46 |
| Parity | 0.72 | -2.54 ~ 3.99 | 0.15 | -1.07 ~ 1.36 | 0.081 | -1.29 ~ 1.45 | 0.50 | -1.30 ~ 2.29 |
| Pre-pregnancy body weight | -0.042 | -0.20 ~ 0.11 | -0.046 | -0.10 ~ 0.011 | -0.022 | -0.086 ~ 0.043 | 0.025 | -0.059 ~ 0.11 |
| Exposure | ||||||||
| Vaginal delivery without epidural anesthesia | Ref | Ref | Ref | Ref | ||||
| Cesarean section | -7.61 | -14.19~-1.03 | -1.20 | -3.65 ~ 1.26 | -2.29 | -5.05 ~ 0.47 | -4.12 | -7.74~-0.52 |
| Vaginal delivery with epidural anesthesia | 8.67 | 0.034 ~ 17.30 | 4.32 | 1.10 ~ 7.53 | 3.39 | -0.23 ~ 7.01 | 0.96 | -3.78 ~ 5.69 |
| aPFDI-20, Pelvic Floor Distress Inventory-20; POPDI, pelvic floor disorders distress; CRADI, colorectal anal distress; UDI, urinary distress | ||||||||
This study revealed the prevalence of PFD in Japanese women. The prevalence could be considered to be relatively high, affecting 156 (73.6%) women. The affected women could be divided into three groups: 27.8% affected by POPDI, 52.4% affected by CRADI, and 53.8% affected by UDI. The most prevalent PFD symptom was UDI in 114 (53.8%) women, wherein 79 (37.3%) women experienced urine leakage related to increased abdominal pressure. The prevalence of the C-section group was 27 of 44 women (64.1%). The targets included primipara and multipara, thereby suggesting high prevalence in the C-section group (Table 2).
A previous study reported that higher scores were recorded on the PFDI-20 (p = 0.003) questionnaires in late pregnancy and in early postpartum period, rather than in early pregnancy. Hence, postpartum PFD is usually correlated with delivery as a risk factor.16
Limited data is available on the prevalence of PFD in Japanese women; hence, it is significant to assess its prevalence.
Pelvic floor dysfunction is widespread in the immediate postpartum period; it tends to remit until 6 months, although in a considerable number of cases, it persists.17 It is remarkable that our results show high rate of prevalence of PFD even 6–15 months postpartum.
Its prevalence in other countries is relatively variable; for example, in Australia, PFDI prevalence was seen in 97% (n = 196) of patients who answered the questionnaire, with a division of 9% affected by POPDI, 79% by CRADI, and 82% by UDI.2 Conversely, a study on Israeli women showed a division of 12.8% women affected by POPDI, 20.7% by CRADI, and 15.8% by UDI at 3 months postpartum.3
Our study does not show contradictory results for PFD prevalence in Japanese women as compared to those of previous studies. We hypothesized several reasons for the differences observed in our study. The first difference was the mode of delivery. The Australian study enrolled patients with vaginal delivery only, excluding those who underwent cesarean section, which would explain the relatively higher rate. Our study showed low prevalence of cesarean section compared with vaginal delivery. The second difference is the timing of the study period. Women at 3 months postpartum may be less active in their daily lives and may be taking lesser load on their body due to lighter body weight of infants thereby exerting lesser burden on their pelvic floor muscles. This would explain the lower prevalence of PFD in the Israeli study.
To date, no prominent factor has been identified for these differences. However, these differences could arise from the type of perinatal management and timing of study. Therefore, more studies should be conducted in future.
Regarding the association between PFD and delivery mode, 8.67 points higher disease burden score (estimate, 8.67(0.03–17.3)) was observed in the epidural group compared with the non-epidural group (Table 3).
Sartore et al. (2003) have concluded that the use of epidural anesthesia is not associated with symptoms related to perineal trauma and pelvic floor muscle weakness.18 We adjusted the method and the duration of labor for analysis; however, the result of the epidural group showing higher risk for PFD remained unchanged. The measurement tools and methodologies used for assessing pelvic floor function in Sartore’s study were different from those used in this study, thereby explaining the variation in results of the two studies.
It is said that epidural anesthesia is related to the prolonged second stage of labor.4 Vaginal delivery with epidural anesthesia is associated with an increase in instrumental vaginal deliveries, as compared to labor without epidural anesthesia.5 Therefore, it is said that epidural anesthesia harms pelvic floor function. The results of these studies are not contradictory to our results.
Regarding the association between PFD and delivery mode, -7.61 points lower disease burden score (estimate, -7.61(0.03–17.3)) was observed in the cesarean group compared with the non-epidural group (Table 3). This indicates that cesarean section is associated with lower incidence of PFD in postpartum women than is vaginal delivery, either non-epidural or epidural in short term. Furthermore, Baud et al. showed that women after vaginal delivery were more likely to report urinary incontinence than after cesarean section at postpartum 6 years. However, women after cesarean section more frequently reported sexual dysfunction symptoms, in particular more painful intercourse than those who underwent vaginal delivery. We should consider the pros and cons and long-term consequences of the delivery mode.19
Thus, based on the results of our study, it may not be recommended to choose cesarean delivery mode over vaginal based delivery only because of the lower risk of PFD.
Our study shows a high PFD prevalence in women at 6–15 months postpartum. Therefore, accurate diagnosis of women along with appropriate and regular follow up until improvement of their symptoms would be significant.
Regular pelvic floor muscle training in postpartum women (n = 50) shows significant improvements in pelvic floor function as per the PFDI-20 (mean change − 41.8; p < 0.001).20 Therefore, healthcare workers should consider early identification of symptoms to provide healthcare, thereby reducing PFD development. This would be more crucial in the epidural group with higher PFD prevalence. A study reports that in women with relatively mild pelvic floor symptoms, an improvement of 13.5 points in the PFDI-20 score can be considered clinically relevant. This minimal yet significant change can be used for clinical trial planning and evaluation of treatment or intervention effects. Hence, our result of 8.67 points could be considered as a clinical risk. Healthcare workers should therefore inform pregnant women regarding the possible increased risk of pelvic floor disorder with anesthesia.
This study had several limitations. First, PFD-20 is an evaluation of symptoms, not pathology. Hence, even if the prevalence of UDI is high, it is not the same as the severity of stress urinary incontinence. Second, this study was based on data from a single center; therefore, the composition of catchment population and resources are potentially limiting to the generalizability of our results in Japan. This study’s limitation was a low response rate, 67.7%, which raised suspicion that non-responders probably had few pelvic floor disorder symptoms.Third, regarding analytic limitation, we consider instrument delivery and perineal laceration as mediators; we could not divide the effect of these mediators from methods of delivery. Furthermore, the factors that affect the prognosis of PFD, such as episiotomy, birth weight, and fetal biparietal diameter, were considered as predictors, not confounders. However, we think that it would not affect the result. Additionally, as this was an observational study, we were not able to adjust for unmeasured confounders. Therefore, the effect of epidural on PFDI may have been biased. For example, the estimated fetal body weight could have affected the implementation of both, the epidural and PFDI, which could not be investigated in this study. More factors need to be prospectively investigated in future studies.
Even 6–15 months after birth, 73.6% of postpartum women have PFD, with its prevalence being higher in the epidural than in the non-epidural group. To the best of our knowledge, our study is the first to investigate postpartum PFD in Japan.
colorectal anal distress
Colorectal-Anal Distress Inventory with eight items
causal directed acyclic graphs
female pelvic floor disorders
Pelvic Floor Distress Inventory-20
pelvic organ prolapse
pelvic organ prolapse distress
Pelvic Organ Prolapse Distress Inventory with six items
standard deviation
urinary distress
Urinary Distress Inventory with six items
Ethics approval and consent to participate: All experiments and methods were performed in accordance with relevant guidelines and regulations. This study received our institutional ethical review board approval (approval ID, 19-052). All applicants were informed and enrolled by mail, which included the informed consent paper.
Consent for publication: Not applicable.
Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Competing interests: The authors declare that they have no competing interests.
Funding: This study is not supported by any administration or funding.
Authors' contributions: T.S., K.M., and T.T. conceived the presented idea. T.S. and K.M. developed the theory and performed the computations. T.S. and H.M. verified the analytical methods. T.T. encouraged T.S. to investigate this study and supervised the findings of this work. All authors discussed the results and contributed to the final manuscript.
Acknowledgments: Not applicable.
Author’s information: T.S. is working as deputy chief of Obstetrics/Gynecology, K.M. is a well-trained midwife, and T.T. is working as chief of Gastroenterological surgery. As we approached patients in the clinical setting, we have considered the possible high prevalence of PFD in postpartum women; moreover, it continues for a certain period. Then we build the team to investigate the Prevalence and risk factors of pelvic floor disorders after delivery in Japanese women using the PFDI-20.