Maternal adaptations in preparation for parturition predict uncomplicated spontaneous delivery outcome

Pelvic floor symptoms according to the severity of second-degree perineal tears within 12 months post-partum: A longitudinal prospective cohort study

INTRODUCTION

Second-degree perineal tears following vaginal birth are common and presumed to be of little clinical importance. However, the extent of damage to the perineal body varies widely, and there is reason to believe that larger second-degree tears may be associated with more pelvic floor symptoms, compared to lesser form. Therefore, the aim of this study was to assess differences in pelvic floor symptoms according to the severity of second-degree perineal tears up to 12 months post-partum, stratified by parity.

MATERIAL AND METHODS

This was a prospective cohort study conducted at Akershus University Hospital, a tertiary referral hospital in Norway. The study sample consisted of 409 primiparas and 394 multiparas with vaginal births. Perineal tears were classified using the classification system recommended by the Royal College of Obstetricians and Gynecologists. Further, second-degree tears were subclassified as 2A, 2B, or 2C, depending on the percentage of damage to the perineal body. Episiotomies were analyzed as a separate group. Pelvic floor symptoms were assessed using the Karolinska Symptoms After Perineal Tear Inventory (KAPTAIN). A linear mixed model was estimated to assess the trend in pelvic floor symptom scores according to perineal tear category and stratified by parity. The primary and secondary outcome measures were the mean sum scores of the KAPTAIN-Inventory, measured in pregnancy (at 18 weeks of gestation), at 3- and 12 months post-partum, and the reported impact of genital discomfort on quality of life measured in pregnancy and at 12 months post-partum.

RESULTS

There were no significant differences in pelvic floor symptom scores over time, or at any timepoint, between no tear, first-degree tear, or second-degree tear subcategories, for primi-, and multiparas. Pelvic floor symptoms increased from pregnancy to 3 months post-partum and remained higher at 12 months post-partum compared to pregnancy in all perineal tear categories. Compared to primiparas, multiparas reported a significantly higher impact of genital discomfort on quality of life in pregnancy and at 12 months post-partum.

CONCLUSIONS

There were no statistically significant differences in pelvic floor symptoms according to the severity of second-degree perineal tears.

Factors associated with spontaneous vaginal birth in nulliparous women: A descriptive systematic review

PROBLEM

Spontaneous vaginal birth (SVB) rates for nulliparous women are declining internationally.

BACKGROUND

There is inadequate understanding of factors affecting this trend overall and limited large-scale responses to improve women's opportunity to birth spontaneously.

AIM

To undertake a descriptive systematic review identifying factors associated with spontaneous vaginal birth at term, in nulliparous women with a singleton pregnancy.

METHODS

Quantitative studies of all designs, of nulliparous women with a singleton pregnancy and cephalic presentation, who experienced a SVB at term were included. Nine databases were searched (inception to October 2022). Two reviewers undertook quality appraisal; Randomised Controlled Trials (RCTs) with high risk of bias (ROB 2.0) and other designs with (QATSDD) scoring ≤ 50% were excluded.

FINDINGS

Data were abstracted from 90 studies (32 RCTs, 39 cohort, 9 cross-sectional, 4 prevalence, 5 case control, 1 quasi-experimental). SVB rates varied (13%-99%). Modifiable factors associated with SVB included addressing fear of childbirth, low impact antenatal exercise, maternal positioning during second-stage labour and midwifery led care. Complexities arising during pregnancy and regional analgesia were shown to decrease SVB and other interventions, such as routine induction of labour were equivocal.

DISCUSSION

Antenatal preparation (low impact exercise, childbirth education, addressing fear of childbirth) may increase SVB, as does midwifery continuity-of-care. Intrapartum strategies to optimise labour progression emerged as promising areas for further research.

CONCLUSION

Declining SVB rates may be improved through multi-factorial approaches inclusive of maternal, fetal and clinical care domains. However, the variability of SVB rates testifies to the complexity of the issue.

Dysregulated wound healing in the pathogenesis of urogynecologic mesh complications

To test the hypothesis that dysregulated wound healing is associated with Urogynecologic mesh complications, we collected vaginal cell secretions using vaginal swabs after polypropylene mesh implantation in patients with (N = 39) and without (N = 40) complication. A customized multiplex immunoassay measured markers of inflammation (MCP-1, IGFBP-1, IL-2, IL-10, IL-17, PDGF-BB, bFGF, IL-1b, IL-6, IL-12p70, TNF-α), neuroinflammation (IL-1RA, TGF-β, IL-15, IL-18, IL-3, M-CSF), angiogenesis (VEGF), and matrix proteins (fibronectin, tenasin c, thrombospondin-2, lumican) between groups. Patients with complications were younger, heavier, implanted with mesh longer, and more likely to be ever smokers. A 5 kg/m2 BMI increase and ever-smoking were associated with a 2.4-fold and sixfold increased risk of complication, respectively. Patients with the highest tertile of bFGF, fibronectin, thrombospondin-2, TNF-β, or VEGF had an odds ratio (OR) of 11.8 for having a mesh complication while ≥ 3 elevated had an OR of 237 while controlling for age, BMI, and smoking. The highest tertile of bFGF, thrombospondin-2, and fibronectin together perfectly indicated a complication (P < 0.0001). A receiver-operator curve for high bFGF, thrombospondin-2, and fibronectin showed excellent discrimination between complications and controls (AUC 0.87). These data provide evidence of dysregulated wound healing in mesh complications. Modifiable factors provide potential targets for patient counseling and interventions.

Hiatal failure: effects of pregnancy, delivery, and pelvic floor disorders on level III factors

INTRODUCTION AND HYPOTHESIS

The failure of the levator hiatus (LH) and urogenital hiatus (UGH) to remain closed is not only associated with pelvic floor disorders, but also contributes to recurrence after surgical repair. Pregnancy and vaginal birth are key events affecting this closure. An understanding of normal and failed hiatal closure is necessary to understand, manage, and prevent pelvic floor disorders.

METHODS

This narrative review was conducted by applying the keywords "levator hiatus" OR "genital hiatus" OR "urogenital hiatus" in PubMed. Articles that reported hiatal size related to pelvic floor disorders and pregnancy were chosen. Weighted averages for hiatal size were calculated for each clinical situation.

RESULTS

Women with prolapse have a 22% and 30% larger LH area measured by ultrasound at rest and during Valsalva than parous women with normal support. Women with persistently enlarged UGH have 2-3 times higher postoperative failure rates after surgery for prolapse. During pregnancy, the LH area at Valsalva increases by 29% from the first to the third trimester in preparation for childbirth. The enlarged postpartum hiatus recovers over time, but does not return to nulliparous size after vaginal birth. Levator muscle injury during vaginal birth, especially forceps-assisted, is associated with increases in hiatal size; however, it only explains a portion of hiatus variation-the rest can be explained by pelvic muscle function and possibly injury to other level III structures.

CONCLUSIONS

Failed hiatal closure is strongly related to pelvic floor disorders. Vaginal birth and levator injury are primary factors affecting this important mechanism.

Effects of the Oxytocin Hormone on Pelvic Floor Muscles in Pregnant Rats

Background and Objectives: Oxytocin induction is a known risk factor for pelvic floor disorders (PFDs). The aim of the study was to investigate the effects of oxytocin induction on pelvic floor muscles in pregnant rats. Methods: Thirty-two female Wistar rats were included and divided into four groups (n = 8). The groups were as follows: virgin group (group I)-from which muscles were dissected at the beginning of the experiment; spontaneous vaginal delivery (group II) which has delivery spontaneously; saline control group (group III) and oxytocin group (group IV). In groups III and IV, pregnancy was induced on d 21 of pregnancy, with 2.5 mU saline solution or iv oxytocin, respectively, delivered by the intravenous (iv) route in pulses at 10-min intervals for 8 h. Then, the rats were euthanized, the m. coccygeus, m. iliocaudalis and m. pubocaudalis muscles were excised and tissue samples were taken. After histological processing, the vertical and horizontal dimensions of the muscles were analyzed under a light microscope. Results: In group IV; the measurement of the horizontal dimension of the m. pubocaudalis muscles was 50.1 ± 5.4 µm and it was significantly higher than other groups (p < 0.001). In group III; the mean value of the horizontal dimension of m. coccygeus muscle was found to be 49.5 ± 10.9 µm and it was significantly higher than other groups (p < 0.009). Between-group comparisons revealed no difference in mean m. iliocaudalis muscle dimension (p > 0.05). Conclusions: As a result of our study it can say that whether oxytocin induced or not, vaginal birth is a process that affects the pelvic muscles.

Reducing pelvic floor injury by induction of labor

INTRODUCTION AND HYPOTHESIS

We hypothesized that elective induction of labor (eIOL) at 39 weeks is protective of levator ani muscle injury (LAMI) and is associated with decreased pelvic symptoms at 6 weeks postpartum compared to expectant management of labor.

METHODS

Prospective cohort pilot study of uncomplicated, primiparous women with a singleton, vertex gestation enrolled immediately post-vaginal delivery (VD). Subjects were dichotomized into two groups based on labor management: eIOL without complication defined by the ARRIVE trial versus spontaneous VD between 39 weeks0/7 and 42 weeks5/7 or no indication for IOL prior to 40 weeks5/7. The primary outcome was LAMI at 6 weeks postpartum as evidenced by any of the following ultrasound measures: (1) increased levator hiatal area (LHA) > 2500 mm2, (2) increased elasticity index (EI, > 75th quartile) or (3) levator enthesis avulsion.

RESULTS

Analysis represents 45/102 consented women from July 2019-October 2020 (eIOL n = 22 and spontaneous VD, n = 23). Neither maternal, clinical, sociodemographic characteristics nor pelvic symptoms differed between groups. Fewer women had LAMI as defined by the primary outcome with eIOL (n = 5, 23.8%) compared to spontaneous VD (n = 15, 65.2%), p = 0.008. Levator enthesis was more deformable (increased EI) with spontaneous VD as compared to the eIOL [10.66 (8.99) vs. 5.68 (2.93), p = 0.046]. On univariate logistic regression women undergoing spontaneous VD had unadjusted OR of 6.0 (1.6-22.5, p = 0.008) of sustaining LAMI compared to those undergoing eIOL.

CONCLUSIONS

Composite measures of LAMI though not pelvic floor symptoms were markedly increased in women undergoing spontaneous VD compared to those undergoing eIOL at 39 weeks.

Pelvic floor symptoms from first pregnancy up to 8 years after the first delivery: a longitudinal study

BACKGROUND

Despite the strong association between vaginal childbirth and pelvic floor dysfunction, genetic factors, pregnancy, advancing age, and lifestyle also play a role. The pelvic floor undergoes substantial changes during pregnancy which may contribute to pelvic floor dysfunction. On the other hand, these changes may be favorable to allow for vaginal delivery. However, there is a lack of studies assessing pelvic floor symptoms over time according to delivery mode, which includes women prior to delivery.

OBJECTIVE

The aim of this study was to describe urinary incontinence, vaginal symptoms, and bowel control symptoms from 21 weeks of gestation in the first pregnancy and up to 8 years after the first delivery, stratified by delivery mode.

STUDY DESIGN

This is a longitudinal observational cohort study. 300 nulliparous women were recruited during their first pregnancy. Pelvic floor symptoms were assessed at 21 and 37 weeks of gestation, and 6 weeks, 6 months, 12 months and 8 years after first delivery using the International Consultation on Incontinence Questionnaire (ICIQ) modules: the urinary incontinence sum score; the weighted vaginal symptom sum score; the vaginal-associated quality of life score; the bowel control sum score; and the bowel-associated quality of life sum score. Delivery mode at first delivery defined delivery groups as: normal vaginal, operative vaginal and cesarean delivery. A linear mixed model analysis was used to assess symptom scores over time and to assess the differences in symptom scores between the delivery groups.

RESULTS

Of the 300 women included in the study, of which 193 attended the 8-year follow-up. Pelvic floor symptoms differed in women with vaginal and cesarean delivery. The symptom scores showed a non-linear statistically significant trend. In women, who delivered vaginally, there was an increase of urinary incontinence and vaginal symptom scores already during pregnancy. In women, who later delivered by cesarean, there was a decrease of symptoms scores during pregnancy, and overall lower symptom scores compared to women with vaginal delivery until 12 months after first delivery. Pelvic floor symptoms scores increased from 12 months to 8 years after the first delivery and exceeded pregnancy levels in all delivery groups, however overall symptom scores were low. Differences between delivery groups were not statistically significant.

CONCLUSION

Pelvic floor symptoms differed in women with vaginal and cesarean delivery from the first pregnancy up to 8 years after the first delivery. These differences were recognizable already prior to first delivery.

International Urogynecological Consultation (IUC): pathophysiology of pelvic organ prolapse (POP)

INTRODUCTION AND HYPOTHESIS

This manuscript is the International Urogynecology Consultation (IUC) on pelvic organ prolapse (POP) chapter one, committee three, on the Pathophysiology of Pelvic Organ Prolapse assessing genetics, pregnancy, labor and delivery, age and menopause and animal models.

MATERIALS AND METHODS

An international group of urogynecologists and basic scientists performed comprehensive literature searches using pre-specified terms in selected biomedical databases to summarize the current knowledge on the pathophysiology of the development of POP, exploring specifically factors including (1) genetics, (2) pregnancy, labor and delivery, (3) age and menopause and (4) non-genetic animal models. This manuscript represents the summary of three systematic reviews with meta-analyses and one narrative review, to which a basic scientific comment on the current understanding of pathophysiologic mechanisms was added.

RESULTS

The original searches revealed over 15,000 manuscripts and abstracts which were screened, resulting in 202 manuscripts that were ultimately used. In the area of genetics the DNA polymorphisms rs2228480 at the ESR1 gene, rs12589592 at the FBLN5 gene, rs1036819 at the PGR gene and rs1800215 at the COL1A1 gene are significantly associated to POP. In the area of pregnancy, labor and delivery, the analysis confirmed a strong etiologic link between vaginal birth and symptoms of POP, with the first vaginal delivery (OR: 2.65; 95% CI: 1.81-3.88) and forceps delivery (OR: 2.51; 95% CI: 1.24-3.83) being the main determinants. Regarding age and menopause, only age was identified as a risk factor (OR : 1.102; 95% CI: 1.02-1.19) but current data do not identify postmenopausal status as being statistically associated with POP. In several animal models, there are measurable effects of pregnancy, delivery and iatrogenic menopause on the structure/function of vaginal support components, though not on the development of POP.

CONCLUSIONS

Genetics, vaginal birth and age all have a strong etiologic link to the development of POP, to which other factors may add or protect against the risk.

Longitudinal Study of Pelvic Floor Characteristics Before, During, and After Pregnancy in Nulliparous Women

OBJECTIVES

To investigate the changes in the pelvic floor before, during, and after pregnancy in the same collective of nulliparous women.

METHODS

In a prospective observational pilot study between April 2015 and June 2019 in nulliparous women with planned pregnancy, we used the pelvic organ prolapse quantification (POP-Q) system; a 2-dimensional (2D) sonography to investigate the bladder neck, cervix, and anorectal junction positions; and a 3D/4D sonography to measure the hiatus of the levator ani muscle (LH area) during Valsalva maneuver. Five visits were planned: 1 before, 3 during, and 1 visit after pregnancy.

RESULTS

Twenty-four women participated in the study. We achieved a minimum of 2 visit measurements from 10 women who became pregnant. The LH area decreased during the first trimester and then increased until the third trimester. Postpartum, the LH area reached the prepregnancy state. We observed changes in the bladder neck mobility, bladder neck position, cervix, and anorectal junction from the first trimester. Postpartum, the bladder neck mobility was higher, and the position of the bladder neck and anorectal junction was lower than before pregnancy. We observed no remarkable changes in the POP-Q state during pregnancy.

CONCLUSION

This was the first study to investigate pelvic floor characteristics in the same collective before, during, and after pregnancy. We observed pelvic floor changes from the prepregnancy state to the first trimester to postpartum. The study results need to be confirmed in a larger study.

Application of pelvic floor ultrasound during pregnancy to detect patients at risk of cesarean section due to failure of labor progression in a Spanish population

OBJECTIVE

Our study is aimed at evaluating the characteristics of the pelvic floor, assessed through transperineal ultrasound, since it may influence or increase the possibility of having a cesarean delivery, with the objective of acting on those variables that can be modified during pregnancy.

STUDY DESIGN

Transperineal ultrasound was performed on 109 primiparous pregnant women in their first trimester of pregnancy, recruited between May 2018 and February 2019, with the purpose of studying the hiatus area at rest, retention and Valsalva. We have reassessed them at the end of pregnancy and delivery data were recorded. We selected 8 patients as case-study, who had cesarean section delivery due to failure of labor progression. We selected 4 control-cases for each, reaching the total of 32 controls, with similar age and body mass index, to avoid obtaining a biased result from these data.

RESULTS

In the study of hiatal areas, patients who delivered by cesarean section had a smaller hiatal area at rest, during levator ani muscle contraction and during Valsalva maneuver, at all visits. In early pregnancy, the range of the resting hiatal area was 13.8 ± 2.0 cm² for cesarean sections, compared to 16.2 ± 2.7 cm² for vaginal deliveries with an OR of 0.57 (0.34-0.95, 95% CI). For hiatal area on Valsalva, the OR was 0.55 (0.35-0.88, 95% CI). Therefore, the smaller the hiatal area, the greater the possibility of cesarean section. At the end of pregnancy, between 34 and 36 weeks of gestation, the OR of hiatal area on Valsalva was 0.78 (0.60-1.00, 95% CI).

CONCLUSION

The hiatus area measured by transperineal ultrasonography at the beginning and at the end of the pregnancy may be useful to identify the patients who are at a higher risk of cesarean delivery due to failure of labor progression.

Recognition and Management of Pelvic Floor Disorders in Pregnancy and the Postpartum Period

Often considered a condition of aging women, pelvic floor disorders may initially present in pregnancy and postpartum, having a negative impact on quality of life during this important time in a woman's life. This review outlines the clinical approach to implementing pelvic health into obstetric care through education and promotion of pelvic health in pregnancy, screening for pelvic floor disorders routinely, and providing support through resources, treatment, and referrals if pelvic floor disorders develop during pregnancy and postpartum.

Changes of pelvic organ prolapse and pelvic floor dysfunction throughout pregnancy in singleton primigravidas: A prospective cohort study

OBJECTIVE

To document the deterioration in pelvic organ support occurring throughout all trimesters during the first pregnancy of women with no known risk factors. Secondarily to make a comprehensive review in order to verify the current findings and methodologies of similar studies in the literature.

STUDY DESIGN

In this prospective study, forty-one primigravid women with a singleton pregnancy were recruited during their first trimester. During follow-up pelvic organ support changes were documented by using Pelvic Organ Prolapse Quantification (POP-Q) system. Additionally, pelvic floor muscle strength examination, by modified Oxford scoring (MOS), and symptom assessment by Pelvic Floor Distress Inventory-Short Form (PFDI-20) were performed at three time points: first (T1), second (T2), and third trimester (T3) (n = 33). The Wilcoxon test was performed to test the significance of pairwise differences. Spearman correlation coefficient was estimated to determine the linear association of the findings.

RESULTS

Both distal and proximal anterior and posterior vaginal walls (Points Aa, Ba, Ap and Bp) with cervix (C) descended towards the hymen, throughout first pregnancy with a significant caudal shift on progressing from T2 to T3 (p ≤ 0.017). Posterior fornix (Point D) made a non-significant cranial shift (p = 0.527). The genital hiatus, perineal body and total vaginal length increased significantly (p ≤ 0.001). No significant difference in MOS was observed throughout pregnancy. The scores of PFDI-20 with all its domains worsened significantly during pregnancy, especially in T3 (p ≤ 0.011). Moderate correlations were observed between posterior vaginal descent and anorectal symptoms (rho 0.427, p < 0.05), and between the changes in genital hiatus and prolapse symptoms (rho 0.406, p < 0.05).

CONCLUSION

A significant descent both in all compartments of vaginal wall and perineum with an increase in total vaginal length, was observed together with an associated pelvic floor dysfunction throughout the first pregnancy of women.

Role of lysyl oxidase like 1 in regulation of postpartum connective tissue metabolism in the mouse vagina†

Pelvic organ prolapse (POP) in lysyl oxidase like-1 knockout (Loxl1 KO) mice occurs primarily in parous mice and is rare in nulliparous mice. We determined the effect of Loxl1 deficiency on postpartum regulation of connective tissue metabolism genes and degradative enzyme activity in the vagina at 20 days gestation or 4 h, 48 h, 7 days, 15 days, 25 days, 7 weeks, or 12 weeks postpartum. Nulliparous Loxl1 KO and wildtype (WT) mice aged 11, 18, or 23 weeks were controls. Gene expression and enzyme activity were assessed using real-time quantitative reverse transcription PCR and fluorescein conjugated gelatin zymography, respectively. Parity, but not aging, had a significant influence on gene expression both with time postpartum and between KO and WT mice. Mmp2, Timp1, Timp2, Timp3, Timp4, Col1a1, Col3a1, Acta2, and Bmp1 were differentially expressed between KO and WT mice. Correlational analysis of gene-gene pairs revealed 10 significant differences between parous KO and WT groups, 5 of which were due to lack of co-expression of Bmp1 in KO mice. The overall enzyme activity that could be attributed to MMPs was significantly higher in WT compared to KO mice both 25 days and 12 weeks postpartum, and MMP activity was significantly lower 15 days and 25 days postpartum compared to KO nulliparous controls, but not WT. These findings suggest that Loxl1 deficiency combined with parity has a significant impact on postpartum regulation of connective tissue metabolism, particularly as it relates to co-expression of Bmp1 and altered proteolytic activity.

Malmström vacuum or Kielland forceps: which causes more damage to pelvic floor?

OBJECTIVE

To determine whether differences exist in the rate of levator ani muscle (LAM) avulsion between women who had undergone either Malmström vacuum delivery (MVD) or Kielland forceps delivery (KFD), allowing for potential confounding factors.

METHODS

This was a prospective observational study of nulliparous women undergoing instrumental delivery using Malmström vacuum extractor or Kielland forceps, at two hospital centers in Spain. Fetal head position (anterior, posterior or transverse) and fetal head station (low or mid) were assessed by ultrasound and digital examination, respectively. Avulsion was defined on tomographic ultrasound imaging as an abnormal insertion of the LAM in the three central slices from the plane of minimal hiatal dimensions.

RESULTS

In total, 414 patients were included in the study (212 MVD and 202 KFD). We observed a higher rate of LAM avulsion in the KFD group (KFD 49.5% vs MVD 32.5%; P = 0.001). When the results were evaluated according to fetal head position and station, we observed no differences in LAM avulsion. The crude odds ratio (OR) for the difference in avulsion between women in the KFD and MVD groups was 2.03 (95% CI, 1.36-3.03). However, when adjusted for duration of second stage of labor, fetal head circumference and fetal head station, the OR was no longer statistically significant (OR, 2.14 (95% CI, 0.95-4.85); P = 0.068).

CONCLUSION

When potential confounding factors are taken into account, the rate of LAM avulsion does not differ between women according to whether they have undergone KFD or MVD. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Device to predict pelvic floor integrity during vaginal delivery: an intra- and interrater reliability study of the Epi-no distensibility measurement

Objective: To determine the test-retest reliability of the pelvic floor distensibility evaluation with Epi-no^® device.Methods: Prospective, blinded observational study with 32 women pregnant from 35 gestational weeks. An Epi-no^® balloon was inflated within the pregnant woman's vagina and the maximum circumference achieved was measured using a standard metric measuring tape. Measurements were performed twice in a day by two physiotherapists in a randomized order. Intraobserver reproducibility was obtained with another evaluation 7-14 d after the initial examination. The intraclass correlation coefficient (ICC) was used to determine the intra and interrater reliability and the respective 95% confidence intervals with an alpha level of 0.05.Results: From a total of 32 included pregnant women, 28 were analyzed; they were 29.3 (±5.97) years old, were at 37 (±1.3) weeks' gestation and presented a mean Epi-no^® circumference of 20.4 (±2.4) cm. Regarding the intraobserver analysis, examiner 1 observed a maximum circumference of 20.6 (±2.6) cm in the first evaluation and 20.2 (±2.4) cm in the second evaluation, with good reliability (ICC = 0.85). Examiner 2 observed 19.7 (±2.4) cm in the first evaluation and 21.0 (±2.0) cm in the second one, with moderate reliability (ICC = 0.58). Regarding the interobserver analysis, there was good reliability on two evaluation days, with an ICC of 0.76 and 0.82, respectively.Conclusions: Epi-no^® device is a reliable device for physiotherapists to measure pelvic floor distention during pregnancy.

The effect of childbirth on urinary incontinence: a matched cohort study in women aged 40-64 years

BACKGROUND

The relative impact of age, pregnancy and vaginal delivery on urinary incontinence is still an unresolved issue that involves the controversial question about the protective effect of cesarean delivery.

OBJECTIVE

The purpose of this study was to estimate and compare the effect size of 1 pregnancy, 1 vaginal delivery, and the derived protective effect of cesarean delivery for different aspects of urinary incontinence in women 40-64 years old, all 20 years after birth.

STUDY DESIGN

This Swedish nationwide matched cohort study involved 14,335 women. Data from 3 restricted, randomly selected, source cohorts of (1) nulliparous women who were unexposed to childbirth (n=9136), (2) primiparous women who had experienced cesarean delivery and who had been exposed to 1 pregnancy (n=1412), and (3) primiparous women who had been exposed to 1 pregnancy followed by vaginal delivery (n=3787) were retrieved from The Swedish Medical Birth Register and Statistics Sweden and surveyed in 2008 and 2014, respectively. Parous women were all assessed 20 years postnatally. One-to-one matching with an interval for pairing of 3 years and 3 body mass index units was used in women 40-64 years old with information about body mass index (kilograms/square meters) and urinary incontinence. The procedure succeeded in 2630 of 2635 women (99.8%) and resulted in an adequate distribution of age and body mass index between groups. The surveys used a postal- and an internet-based questionnaire with validated questions for various aspects of urinary incontinence. Fisher's exact test and the Mann-Whitney U test were used for comparisons between matched groups; trend was analyzed with Mantel-Haenszel statistics. Predicted, age-related values of different aspects of urinary incontinence were obtained by logistic regression analysis.

RESULTS

Pregnancy increased the prevalence of urinary incontinence from 20.1-30.1% (odds ratio, 1.71; 95% confidence interval, 1.43-2.05; P<.0001]. Urinary incontinence increased further after vaginal delivery to 43.0% (odds ratio, 1.75; 95% confidence interval, 1.49-2.05; P<.0001); "moderate" and "severe" urinary incontinence increased from 12.7-19.5% (odds ratio, 1.67; 95% confidence interval, 1.35-2.07; P <.0001). There was a parallel increase in urinary incontinence from 40-65 years of age in nulliparous and vaginally and cesarean delivered women. Cesarean delivery, compared with vaginal delivery, was associated with a 30.0% reduction of urinary incontinence (P<.0001) and a 35-52% reduction of more severe grades of urinary incontinence (P<.0001) and was unaffected by age.

CONCLUSION

Both pregnancy and vaginal delivery incurred an increased risk of urinary incontinence in the long term. The age-related gap for urinary incontinence between nulliparous and primiparous women who were delivered by vaginal delivery or cesarean delivery was constant between parallel trajectories that spanned ages from 40-64 years. The calculated protective effect of cesarean delivery was unaltered and significant during the same age interval.

High-Low Impact Exercise Program Including Pelvic Floor Muscle Exercises Improves Pelvic Floor Muscle Function in Healthy Pregnant Women - A Randomized Control Trial

Background: Pregnancy and high-impact activity are considered as risk factors for pelvic floor dysfunctions, including urinary incontinence.

Aim: To investigate whether a structured exercise program, including high- and low-impact aerobics and supported by pelvic floor muscle exercises, improves the neuromuscular activity of the pelvic floor and does not reduce the quality of life in terms of urinary incontinence in healthy pregnant women.

Methods: This was a randomized control trial among 97 Caucasian healthy nulliparas in uncomplicated pregnancies (age 30 ± 4 years, 21 ± 5 weeks of gestation; mean ± SD). Women were assessed for pelvic floor muscle functions with surface electromyography (EMG) using vaginal probes and using the Incontinence Impact Questionnaire (IIQ). Only women able to contract pelvic floor muscles and with good quality of life based on IIQ were included for the study. Seventy women in the experimental group took part in a supervised exercise program including high-low impact aerobics and pelvic floor muscle exercises three times a week. Twenty-seven controls did not receive any exercise intervention. After 6 weeks both groups were re-tested with EMG and IIQ. Post- and pre-exercise program changes in each group were analyzed using a repeated-measures ANOVA.

Results: Women in the experimental group improved the neuromuscular activity of the pelvic floor in some motor tasks without any adverse outcomes of the intervention. After the exercise program we observed in the experimental group significantly higher EMG amplitude in the pelvic floor muscles during 3-s contractions (p = 0.014). We also noticed a beneficial trend in the increase of neuromuscular activity during 10- and 60-s contractions, but the changes were not statistically significant. The exercising women substantially improved their abilities for relaxation following 3- and 10-s contractions (p = 0.013 and p < 0.001). In controls, we reported no statistically significant improvement in either of the motor tasks. All study participants maintained good quality of life related to urinary incontinence.

Conclusion: Prenatal exercise programs that include high- and low-impact aerobics and are supported by pelvic floor muscle exercises should be recommended for pregnant women, especially those who are accustomed to higher exercise intensity before pregnancy. Nevertheless, these recommendations can be directed to continent women who can properly contract pelvic floor muscles.

ISRCTN. DOI: 10.1186/ISRCTN92265528: “Pelvic floor muscle training with surface electromyography”, retrospectively registered on the 25th of July, 2016.

Automatic segmentation of puborectalis muscle on three-dimensional transperineal ultrasound

OBJECTIVES

The introduction of three-dimensional (3D) analysis of the puborectalis muscle (PRM) for diagnostic purposes into daily practice is hindered by the need for appropriate training of observers. Automatic segmentation of the PRM on 3D transperineal ultrasound may aid its integration into clinical practice. The aims of this study were to present and assess a protocol for manual 3D segmentation of the PRM on 3D transperineal ultrasound, and to use this for training of automatic 3D segmentation method of the PRM.

METHODS

The data used in this study were derived from 3D transperineal ultrasound sequences of the pelvic floor acquired at 12 weeks' gestation from nulliparous women with a singleton pregnancy. A manual 3D segmentation protocol was developed for the PRM based on a validated two-dimensional segmentation protocol. For automatic segmentation, active appearance models of the PRM were developed, trained using manual segmentation data from 50 women. The performances of both manual and automatic segmentation were analyzed by measuring the overlap and distance between the segmentations. Intraclass correlation coefficients (ICCs) and their 95% CIs were determined for mean echogenicity and volume of the puborectalis muscle, in order to assess inter- and intraobserver reliabilities of the manual method using data from 20 women, as well as to compare the manual and automatic methods.

RESULTS

Interobserver reliabilities for mean echogenicity and volume were very good for manual segmentation (ICCs 0.987 and 0.910, respectively), as were intraobserver reliabilities (ICCs 0.991 and 0.877, respectively). ICCs for mean echogenicity and volume were very good and good, respectively, for the comparison of manual vs automatic segmentation (0.968 and 0.626, respectively). The overlap and distance results for manual segmentation were as expected, showing an average mismatch of only 2-3 pixels and reasonable overlap. Based on overlap and distance, five mismatches were detected for automatic segmentation, resulting in an automatic segmentation success rate of 90%.

CONCLUSIONS

This study presents a reliable manual segmentation protocol and automatic 3D segmentation method for the PRM, which will facilitate future investigation of the PRM, allowing for the reliable measurement of potentially clinically valuable parameters such as mean echogenicity. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology Published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Impact of subsequent pregnancies on pelvic floor functional anatomy

INTRODUCTION AND HYPOTHESIS

Vaginal childbirth clearly has an effect on pelvic floor anatomy, and pregnancy itself also likely plays a role. This study investigated the effects of consecutive pregnancies by comparing pelvic organ support and function in urogynecological patients delivered by cesarean section (CS) only.

METHODS

This was a retrospective study using 161 archived data sets of urogynecological patients delivered exclusively by CS presenting with symptoms of pelvic floor dysfunction between 2007 and 2015. Patients had undergone an interview, clinical examination using the Pelvic Organ Prolapse Quantification (POP-Q) system, and 3D/4D translabial ultrasound (TLUS) using Voluson systems. Measures of functional pelvic floor anatomy were obtained from stored ultrasound (US) volumes at a later date, using proprietary software, and blinded against all other data.

RESULTS

One hundred and sixty-one women delivered exclusively by CS were seen in a urogynecological clinic. Volume data analysis was possible in 151 patients. Mean age was 52 (26-82) years, with a mean body mass index (BMI) of 29.5 (18.4-48.7) kg/m². Forty-three (28.5%) women had one CS, 67 (44.4%) had two, and 41 (27.1%) had three or more. On multivariate analysis, adjusting for age, BMI, history of hysterectomy, and incontinence or prolapse surgery, there were no significant differences between groups.

CONCLUSIONS

On comparing women with one, two, or three or more CS, we found no significant differences in any measured sonographic parameters of pelvic organ descent and pelvic floor muscle function. This implies that subsequent pregnancies after the first are unlikely to exert significant additional effects on pelvic floor functional anatomy.

Pregnancy and parturition negatively impact vaginal angle and alter expression of vaginal MMP-9

BACKGROUND

Parity is the greatest risk factor for the development of pelvic organ prolapse. The normally supported vagina is pulled up and back over the levator ani. Loss of vaginal angulation has been associated with prolapse and may represent injury to the vaginal supportive tissues.

OBJECTIVE

We proposed and examined the following hypotheses: (1) pregnancy and delivery impact vaginal support, leading to loss of vaginal angle; (2) vaginal angulation is restored postpartum; and (3) uncomplicated vaginal delivery (VD) is associated with accelerated remodeling of the vaginal fibrillar matrix.

MATERIALS AND METHODS

We prospectively enrolled a cohort of nulliparas in the first trimester of pregnancy, and abstracted demographic and delivery data. Metalloproteinase 9 (MMP-9) activity in the vagina was determined in the first and third trimesters and 1 year postpartum using a substrate activity assay. Uncomplicated VD was defined as none of the following: cesarean delivery, forceps or vacuum use, shoulder dystocia, obstetric anal sphincter laceration, or prolonged second-stage labor. Women were grouped dichotomously for comparison based on this definition. A subset of participants underwent transperineal ultrasound.

RESULTS

We enrolled 173 women with mean age of 25 ± 6 years and a body mass index of 20 ± 7 kg/m². Of the women, 67% identified as white/Caucasian, 27% black/African American, or 6% Hispanic/Latina. The mean delivery age was 39 ± 3 weeks, with 59% of participants experiencing uncomplicated VD. The MMP-9 median activity (ng/mg protein) was 242.0 (IQR, 18.7, 896.8; n = 157) in the first trimester, 130.8 (IQR, 14.6, 883.8; n = 148) in the third trimester, and 463.5 (IQR, 92.2, 900.0; n = 94) postpartum. The MMP-9 activity increased between the third trimester and 1 year postpartum (P = .006), with no significant difference between MMP-9 values in the first and third trimesters (P = .674). The vaginal angle became less acute from the first to the third trimester, and this change persisted postpartum. The vaginal angulation over the levator plate became more acute between the third trimester and postpartum in women who experienced uncomplicated VD compared to those who did not (-6.4 ± 22.1 degrees vs 17.5 ± 14.8 degrees; P = .017). Higher MMP-9 activity postpartum was associated with uncomplicated VD, with 67% of women in the third tertile achieving uncomplicated VD versus 39% in the first tertile (P = .029).

CONCLUSION

Loss of vaginal angulation occurs between trimesters, and women do not recover their baseline resting angle postpartum. MMP-9 activity increases postpartum. Women experiencing uncomplicated VD demonstrate higher postpartum MMP-9 activity and are more likely to have recovered their vaginal angle.

The Epidemiology of Pelvic Floor Disorders and Childbirth: An Update

Using a lifespan model, this article presents new scientific findings regarding risk factors for pelvic floor disorders (PFDs), focusing on the role of childbirth in the development of single or multiple coexisting PFDs. Phase I of the model includes predisposing factors, such as genetic predisposition and race. Phase II includes inciting factors, such as obstetric events. Prolapse, urinary incontinence (UI), and fecal incontinence (FI) are more common among vaginally parous women, although the impact of vaginal delivery on risk of FI is less dramatic than prolapse and UI. Phase III includes intervening factors, such as age and obesity.

Pregnancy-induced adaptations in intramuscular extracellular matrix of rat pelvic floor muscles

BACKGROUND

Birth trauma to pelvic floor muscles is a major risk factor for pelvic floor disorders. Intramuscular extracellular matrix determines muscle stiffness, supports contractile component, and shields myofibers from mechanical strain.

OBJECTIVE

Our goal was to determine whether pregnancy alters extracellular matrix mechanical and biochemical properties in a rat model, which may provide insights into the pathogenesis of pelvic floor muscle birth injury. To examine whether pregnancy effects were unique to pelvic floor muscles, we also studied a hind limb muscle.

STUDY DESIGN

Passive mechanical properties of coccygeus, iliocaudalis, pubocaudalis, and tibialis anterior were compared among 3-month old Sprague-Dawley virgin, late-pregnant, and postpartum rats. Muscle tangent stiffness was calculated as the slope of the stress-sarcomere length curve between 2.5 and 4.0 μm, obtained from a stress-relaxation protocol at a bundle level. Elastin and collagen isoform concentrations were quantified by the use of enzyme-linked immunosorbent assay. Enzymatic and glycosylated collagen crosslinks were determined by high-performance liquid chromatography. Data were compared by the use of repeated-measures, 2-way analysis of variance with Tukey post-hoc testing. Correlations between mechanical and biochemical parameters were assessed by linear regressions. Significance was set to P < .05. Results are reported as mean ± SEM.

RESULTS

Pregnancy significantly increased stiffness in coccygeus (P < .05) and pubocaudalis (P < .0001) relative to virgin controls, with no change in iliocaudalis. Postpartum, pelvic floor muscle stiffness did not differ from virgins (P > .3). A substantial increase in collagen V in coccygeus and pubocaudalis was observed in late-pregnant, compared with virgin, animals, (P < .001). Enzymatic crosslinks decreased in coccygeus (P < .0001) and pubocaudalis (P < .02) in pregnancy, whereas glycosylated crosslinks were significantly elevated in late-pregnant rats in all pelvic floor muscles (P < .05). Correlations between muscle stiffness and biochemical parameters were inconsistent. In contrast to the changes observed in pelvic floor muscles, the tibialis anterior was unaltered by pregnancy.

CONCLUSIONS

In contrast to other pelvic tissues, pelvic floor muscle stiffness increased in pregnancy, returning to prepregnancy state postpartum. This adaptation may shield myofibers from excessive mechanical strain during parturition. Biochemical alterations in pelvic floor muscle extracellular matrix due to pregnancy include increase in collagen V and a differential response in enzymatic vs glycosylated collagen crosslinks. The relationships between pelvic floor muscle biochemical and mechanical parameters remain unclear.

Pregnancy-induced adaptations in the intrinsic structure of rat pelvic floor muscles

OBJECTIVE

Maternal birth trauma to the pelvic floor muscles (PFMs) is a major risk factor for pelvic floor disorders. Modeling and imaging studies suggest that demands placed on PFMs during childbirth exceed their physiologic limits; however many parous women do not sustain PFM injury. Here we determine whether pregnancy induces adaptations in PFM architecture, the strongest predictor of muscle function, and/or intramuscular extracellular matrix (ECM), responsible for load bearing. To establish if parallel changes occur in muscles outside of the PFM, we also examined a hind limb muscle.

STUDY DESIGN

Coccygeus, iliocaudalis, pubocaudalis, and tibialis anterior of 3-month-old Sprague-Dawley virgin, mid-pregnant, and late-pregnant; 6-month-old virgin; and 4- and 12-week postpartum rats (N = 10/group) were fixed in situ and harvested. Major architectural parameters determining muscle's excursion and force-generating capacity were quantified, namely, normalized fiber length (Lfn), physiologic cross-sectional area, and sarcomere length. Hydroxyproline content was used as a surrogate for intramuscular ECM quantity. Analyses were performed by 2-way analysis of variance with Tukey post hoc testing at a significance level of .05.

RESULTS

Pregnancy induced a significant increase in Lfn in all PFMs by the end of gestation relative to virgin controls. Fibers were elongated by 37% in coccygeus (P < .0001), and by 21% in iliocaudalis and pubocaudalis (P < .0001). Importantly, no Lfn change was observed in the tibialis anterior. Physiologic cross-sectional area and sarcomere length were not affected by pregnancy. By 12 weeks' postpartum, Lfn of all PFMs returned to the prepregnancy values. Relative to virgin controls, ECM increased by 140% in coccygeus, 52% in iliocaudalis, and 75% in pubocaudalis in late-pregnant group, but remained unchanged across time in the tibialis anterior. Postpartum, ECM collagen content returned to prepregnancy levels in iliocaudalis and pubocaudalis, but continued to be significantly elevated in coccygeus (P < .0001).

CONCLUSION

This study demonstrates that pregnancy induces unique adaptations in the structure of the PFMs, which adjust their architectural design by adding sarcomeres in series to increase fiber length as well as mounting a substantial synthesis of collagen in intramuscular ECM.