Investigation of correlation between diameters of pelvic inlet and outlet planes and female pelvic floor dysfunction

Contributory effects of individual characteristics on pelvic floor distress in women with pelvic floor dysfunctions

OBJECTIVE

To determine individual characteristics (i.e. sociodemographic and medical, obstetric and gynecological, and musculoskeletal and anthropometric parameters) for greater pelvic floor distress (PFD).

METHODS

A cross-sectional study was performed in 253 women with pelvic floor dysfunction. PFD was assessed using the Pelvic Floor Distress Inventory-20 (PFDI-20). The score of Urogenital Distress Inventory-6 (UDI-6) was used to perform secondary analyses. Sociodemographic, medical, and obstetric & gynecological parameters were recorded. Waist and hip circumferences and pelvic diameters were measured as anthropometric parameters. Pearson test, t-test, and linear regression analyses were conducted with a significance level of 0.05.

RESULTS

Education level (r = -0.23, p < .001; r = -0.24, p < .001), number of vaginal births (r = 0.15, p = .012; r = 0.12, p = .048), total vaginal birth weight (r = 0.15, p = .021; r = 0.16, p = .019), and Body Mass Index (r = 0.12, p = .043; r = 0.16, p = .007) were significantly correlated with the higher PFDI-20 and UDI-6 scores. The maternal age at the first vaginal birth (r = -0.13, p = .049) and pelvic antero-posterior diameter (r = 0.17, p = .013) were also significantly correlated with higher UDI-6 score. Linear regression analyses revealed that younger age (Beta coefficient (β) = -1.10, p = .005), greater symptom duration (β = 2.28, p = .001), the presence of chronic cough/constipation (β = 25.72, p = .001), and increased total vaginal birth weight (β = 2.38, p = .030) were associated with the greater PFDI-20 score. Increased pelvic antero-posterior diameter (β = 0.88, p = .049) was a contributory factor for the greater UDI-6 score.

CONCLUSION

This study showed that younger age, chronic cough/constipation, higher total vaginal birth weight, greater symptom duration, and pelvic antero-posterior diameter can be contributors of greater PFD. We suggest further longitudinal studies that better reveal the causal relationship between individual characteristics and PFD.

The Influence of Obstetric Factors on the Occurrence of Pelvic Floor Dysfunction in Women in the Early Postpartum Period

Background

This study aimed to analyze the effect of obstetric factors on the development of pelvic floor dysfunction (PFD) in women in the early postpartum period.

Methods

Clinical data of 300 women who were reviewed in our outpatient clinic from July 2016 to December 2019 in the postpartum period were retrospectively analyzed. The occurrence of pelvic organ prolapse (POP) and stress urinary incontinence (SUI) was assessed using the Pelvic Organ Prolapse Quantification System and International Consultation on Incontinence Questionnaire Short Form. Factors affecting the occurrence of PFD in women in the early postpartum period were analyzed using univariate and multifactorial logistic regression models.

Results

A total of 46 cases of POP (15.33%) and 82 of SUI (27.33%) occurred in 300 women at 6–8 weeks after birth. Unconditional logistic regression confirmed that age ≥35 years, vaginal delivery, BMI before delivery ≥ 25 kg/m², perineal tear, protracted or prolonged second stage of labor, and fetal macrosomia were risk factors influencing the occurrence of POP (OR > 1, P < 0.05), whereas age ≥ 35 years, vaginal delivery, perineal tear, protracted or prolonged second stage of labor, fetal macrosomia, and SUI during pregnancy were risk factors influencing the occurrence of SUI (OR> 1, P< 0.05).

Conclusion

Obstetric factors such as age, mode of delivery, perineal tear, protracted or prolonged second stage of labor, and fetal macrosomia may increase the risk of developing PFD in women in the early postpartum period; hence, these risk factors should be correctly identified and promptly addressed to prevent the development of PFD.

Assessing the role of the pelvic canal in supporting the gut in humans

The human pelvic canal (true pelvis) functions to support the abdominopelvic organs and serves as a passageway for reproduction (females). Previous research suggests that these two functions work against each other with the expectation that the supportive role results in a narrower pelvic midplane, while fetal passage necessitates a larger opening. In this research, we examine how gut size relates to the size and shape of the true pelvis, which may have implications on how gut size can influence pelvic floor integrity. Pelves and in vivo gut volumes were measured from CT scans of 92 adults (48 female, 44 male). The true pelvis was measured at three obstetrical planes (inlet, midplane, outlet) using 11 3D landmarks. CT volumetry was used to obtain an individual’s gut size. Gut volume was compared to the pelvic planes using multiple regression to evaluate the relationship between gut size and the true pelvis. We find that, in males, larger gut sizes are associated with increased mediolateral canal dimensions at the inlet and midplane. In females, we find that larger gut sizes are associated with more medially-projecting ischial spines and an anteroposteriorly longer outlet. We hypothesize that the association of larger guts with increased canal width in males and increased outlet length in females are adaptations to create adequate space for the gut, while more medially projecting ischial spines reduce the risk of pelvic floor disorders in females, despite its possible spatial consequences for fetal passage.

The evolution of pelvic canal shape and rotational birth in humans

BACKGROUND

The human foetus typically needs to rotate when passing through the tight birth canal because of the complex shape of the pelvis. In most women, the upper part, or inlet, of the birth canal has a round or mediolaterally oval shape, which is considered ideal for parturition, but it is unknown why the lower part of the birth canal has a pronounced anteroposteriorly oval shape.

RESULTS

Here, we show that the shape of the lower birth canal affects the ability of the pelvic floor to resist the pressure exerted by the abdominal organs and the foetus. Based on a series of finite element analyses, we found that the highest deformation, stress, and strain occur in pelvic floors with a circular or mediolaterally oval shape, whereas an anteroposterior elongation increases pelvic floor stability.

CONCLUSIONS

This suggests that the anteroposterior oval outlet shape is an evolutionary adaptation for pelvic floor support. For the pelvic inlet, by contrast, it has long been assumed that the mediolateral dimension is constrained by the efficiency of upright locomotion. But we argue that the mediolateral elongation has evolved because of the limits on the anteroposterior diameter imposed by upright posture. We show that an anteroposteriorly deeper inlet would require greater pelvic tilt and lumbar lordosis, which compromises spine health and the stability of upright posture. These different requirements of the pelvic inlet and outlet likely have led to the complex shape of the pelvic canal and to the evolution of rotational birth characteristic of humans.

Pelvic dimension as a predictor of ureteral injury in gynecological cancer surgeries

BACKGROUND

Ureteral injury is an intractable complication in gynecological cancer surgeries. Identifying risk factors can ensure safety of the ureters intraoperatively. A narrow pelvis is known to exert extra difficulties in pelvic surgeries. However, whether pelvic dimension can affect the risk of ureteral injury in gynecological cancer surgeries is poorly understood. We aimed to evaluate the association between pelvic dimension and the risk of ureteral injury during gynecological cancer surgeries.

METHODS

All patients who had undergone gynecological cancer surgeries were searched from January 2011 to July 2017. We included patients with ureteral injury who had available data of abdominal and pelvic computed tomography for measuring pelvic dimensions. Multivariate condition logistic analysis was used to identify the risk factors independently correlated with ureteral injury in gynecological cancer surgeries.

RESULTS

A total of 43 cases with 86 controls were included in this study. We discovered that a longer anteroposterior diameter of the mid-pelvis (odds ratio [OR] 1.07, 95% confidence interval [CI] 1.01-1.13, P = 0.019) and a shorter transverse diameter of the mid-pelvis (OR 0.92, 95% CI 0.86-0.98, P = 0.013) were associated with ureteral injury in gynecological cancer surgeries. In laparoscopic analysis, a longer anteroposterior diameter of the mid-pelvis (OR 1.11, 95% CI 1.00-1.24, P = 0.041) was a risk factor for ureteral injury. In the analysis of open surgery, a longer transverse diameter of the mid-pelvis (OR 0.79, 95% CI 0.66-0.93, P = 0.006) was a protective factor for ureteral injury.

CONCLUSIONS

This study demonstrated that mid-pelvis dimensions were associated with ureteral injury, but the observed differences were too small. In addition, pelvic inlet dimensions did not appear to relate with ureteral injury. Thus, these pelvimetry measures could not be beneficial in assessing the risk of ureteral injury in gynecological cancer surgeries.

Investigation of correlation between bony pelvis dimensions and pelvic organ prolapse in different compartments

OBJECTIVE

To investigate the association between bony pelvis dimensions and anterior, apical, and posterior compartment pelvic organ prolapse (POP) and explore the mechanism of different types of POP from an anatomical point of view.

STUDY DESIGN

A total of 253 patients with POP were selected as the experimental group (138 patients with anterior compartment defect, 86 with apical compartment defect, and 29 with posterior compartment defect); 253 patients with uterine myoma constituted the control group. Their demographics were recorded, and anteroposterior diameters of the pelvic inlet, intertuberous diameter, and interspinous diameter were measured. One-way analysis of variance, least significant difference t-test, and Student's t-test were used to evaluate the pelvic measurements among the four groups.

RESULTS

The anteroposterior diameter of the pelvic inlet in the apical compartment POP group was smaller than that in the other groups (P < 0.05). Interspinous diameters in the anterior and apical groups were larger than those in the posterior POP and control groups (P < 0.05). Intertuberous diameter in the control group was smaller than that in the anterior and apical POP groups and larger than that in the posterior POP group (P < 0.05).

CONCLUSION

Women with apical compartment POP are more likely to have a smaller anteroposterior diameter. Larger interspinous and intertuberous diameters were associated with anterior and apical POP, and smaller intertuberous diameter was associated with posterior POP.

Sexual dimorphism of the relationship between the gut and pelvis in humans

OBJECTIVES

Obstetric demands have long been considered in the evolution of the pelvis, yet consideration of the interaction of pregnancy, the pelvis, and the gastrointestinal tract (gut) is lacking. Here, we explore sex differences in the relationship of gut volume with body size and pelvic dimensions.

MATERIALS AND METHODS

Computed tomography (CT) scans of living adult Homo sapiens (46 females and 42 males) were obtained to measure in vivo gut volume (GV) and to extract 3D models of the pelvis. We collected 19 3D landmarks from each pelvis model to acquire pelvic measurements. We used ordinary least squares regression to explore relationships between GV and body weight, stature, and linear pelvic dimensions.

RESULTS

The gut-pelvis relationship differs between males and females. Females do not exhibit significant statistical correlations between GV and any variable tested. GV correlates with body size and pelvic outlet size in males. GV scales with negative allometry relative to body weight, stature, maximum bi-iliac breadth, inferior transverse outlet breadth, and bispinous distance in males.

DISCUSSION

The lack of association between GV and body size in females may be due to limits imposed by the anticipation of accommodating a gravid uterus and/or the increased plasticity of the pelvis. The pattern of relationship between GV and the pelvic outlet suggests the role of the bony pelvis in supporting the adominal viscera in females may be small relative to its role in childbirth. We conclude that gut size inference in fossil hominins from skeletal proxies is limited and confounded by sexual dimorphism.

Risk factors for episiotomy during vaginal childbirth: A retrospective cohort study in Western China

OBJECTIVE

To assess the incidence rates and risk factors for episiotomy during vaginal childbirth in a Western China context.

METHODS

A retrospective hospital-based cohort study was conducted using computerized data of 3721 singleton vaginal deliveries after 28 weeks of gestation. Women who underwent episiotomy were compared with those who did not.

RESULTS

The overall prevalence of episiotomy was 44.0% (1636/3721); 52.9% (1458/2756) among primiparas and 18.4% (178/965) among multiparas (P < 0.001). Adjusted risk factors significantly associated with episiotomy included primiparity, prolonged second stage of labor, and labor-management personnel. Risk factors specific to primiparas were increasing maternal age (per year) (OR = 1.04, 95% CI 1.01 to 1.07, P = 0.035), increasing biparietal diameter (per centimeter) (OR = 1.40, 95% CI 1.06 to 1.84, P = 0.017), first stage of labor beyond 10-hour (OR = 1.36, 95% CI 1.10 to 1.68, P = 0.005), and birth weight (per 100 g) (OR = 1.06, 95% CI 1.03 to 1.09, P < 0.001). Birth weight resulted in an adjusted risk increase of 6.1% among primiparas for every 100 additional grams of birth weight. For the analysis stratified by labor-management personnel, moderately experienced midwifery was a risk factor of episiotomy (OR = 1.76, 95% CI 1.21 to 2.56, P = 0.003); midwives with bachelor's degree (OR = 1.47, 95% CI 1.15 to 1.88, P = 0.002), and obstetricians with doctor's degree (OR = 2.00, 95% CI 1.18 to 3.39, P = 0.010) were most likely to perform episiotomy.

CONCLUSION

Episiotomy is still commonly performed in Western China. A survey of maternity care professionals' knowledge of and attitudes towards episiotomy is urgently required to explore the complex reasons for conducting episiotomy.

Age-related trends of lesser pelvic architecture in females and males: a computed tomography pelvimetry study

The pelvis and the spine form a system balancing human skeleton. Within this system, the pelvis adapts to age-related changes in the spine. Previous studies were predominantly focused on changes of pelvic parameters in the sagittal plane. The aim of this study was to reveal age-related changes of lesser pelvic dimensions at different levels of the pelvic cavity in the sagittal and coronal planes and to explore sexual dimorphism in age-related tendencies. The computed tomography pelvimetry was performed on the three-dimensional workstation. The research sample included 211 females aged 18 to 84 years and 181 males aged 18 to 82 years, who underwent an examination at the Riga East University Hospital, Clinical Center “Gailezers,” Latvia. Three pelvic angles and transverse and sagittal diameters of the lesser pelvis were measured at four levels: the inlet, two axial planes in the mid-cavity, and the outlet. The results demonstrated that more pronounced age-related changes occurred in the inlet and the outlet of the lesser pelvis. The mid-cavity was less changing. The transverse diameter between acetabular centers and the sagittal diameter at the level of ischial spines were independent of age. In general, the common age-related trends were observed for pelvic parameters in females and males. A single exception was the proportion of diameters at the level of ischial spines, which decreased in males only. For parameters associated with pelvic floor diseases, age-related changes occurred in the direction of pathology.