Perineal body stretch during labor does not predict perineal laceration, postpartum incontinence, or postpartum sexual function: a cohort study

Occurrence and risk factors for second-degree perineal tears: A prospective cohort study using a detailed classification system

BACKGROUND

The amount of tissue trauma within second-degree perineal tears varies widely. Therefore, subcategorization of second-degree tears and a better understanding of their occurrence and risk factors are needed. The aim of this study was to assess the occurrence of perineal tears when second-degree tears were subcategorized. Furthermore, we aimed to assess the association between variables related to perineal anatomy and other potential risk factors, with second-degree tear subcategories.

METHODS

This prospective cohort study included 880 primiparous and multiparous women giving birth to one child vaginally. Perineal tears were categorized using the classification system recommended by the Royal College of Obstetricians and Gynaecologists. In addition, second-degree tears were subcategorized as 2A, 2B, or 2C according to the percentage of damage to the perineal body. Selected variables related to perineal anatomy were as follows: length of genital hiatus; perineal body length; and previous perineal trauma. Risk factors for second-degree tear subcategories were analyzed using a multinominal regression model.

RESULTS

Perineal tears occurred as follows: first-degree: 35.6% (n = 313), 2A: 16.3% (n = 143), 2B: 9.1% (n = 80), 2C: 6.6% (n = 58), and third- or fourth-degree: 1.6% (n = 14). In total, 169/880 participants underwent an episiotomy. When episiotomies were excluded, the risk for 2B, or 2C tears increased with smaller genital hiatus, larger perineal body, previous perineal trauma, primiparity, higher gestational age, instrumental vaginal delivery and fetal presentation other than occiput anterior.

CONCLUSION

The occurrence of second-degree tear subcategories was 16.3% for 2A tears, 9.1% for 2B tears, and 6.6% for 2C tears. Factors related to perineal anatomy increased the odds for experiencing a second-degree tear in a more severe subcategory.

Effect of Perineal Massage and Warm Compresses Technique in Postpartum Pelvic Floor Dysfunction. A Secondary Analysis from a Randomised Controlled Trial

Pelvic floor dysfunction (PFD) is common to be associated with pregnancy and birth. To date, no research has been done to understand whether the perineal massage and warm compresses technique has an impact on pelvic floor dysfunction. To assess the impact of perineal massage and warm compresses technique during the second stage of labor in pelvic floor dysfunction at 3 and 6 months postpartum. Of the 800 women recruited to randomised controlled trial to prevent perineal trauma, 496 were included in the study, with 242 (48.8%) assigned to the Perineal Massage and Warm Compresses (PeMWaC) group and 254 (51.2%) to the control group (hands-on). Used the Pelvic Floor Distress Inventory-20 (PFDI-20). The questionnaire is divided into three subscales: Urinary (UDI), Colorectal-Anal (CRADI), and Pelvic Organ Prolapse Distress Inventory (POPDI). The PeMWaC group had a significantly higher frequency of intact perineum (p < 0.001) and low-severity vaginal tears (tears without any other degree of perineal trauma) (p = 0.031) compared to the control group, while the control group had significantly more patients who suffered high-severity vaginal/perineal trauma (second degree perineal tears) (p = 0.031) and patients without spontaneous perineal trauma or vaginal tears who underwent episiotomy (p < 0.001). In addition, at 3 months postpartum, women in the control group had a higher Urinary Distress Inventory (UDI) score and global score, compared to the PeMWaC group, and after controlling for confounding variables, the perineal massage and warm compresses technique was associated with lower UDI scores at 3 months postpartum compared to control group. At 6 months postpartum, there were no differences in the UDI or global scores, indicating general recovery from perineal trauma. In addition to reducing perineal trauma during birth, the perineal massage and warm compresses technique was associated with a lower prevalence of early PFD symptoms, mainly urinary distress, at 3 months.Trial registration http://www.ClinicalTrials.gov NCT05854888, retrospectively registered.

Impact of Urinary Incontinence on Postpartum Sexual Function

OBJECTIVE

The aim of the study is to evaluate the incidence of urinary incontinence (UI) and its impact on sexual function among women within 3 years of delivery.

METHODS

This was a cross-sectional study of 531 participants who gave birth by any method in the past 3 years. Participants were administered the Edinburgh Depression Screening Questionnaire, Generalized Anxiety Disorder-7 questionnaire, the Overactive Bladder Symptom Score questionnaire, Incontinence Impact Questionnaire, Sexual Function Questionnaire's Medical Impact Scale, and Decreased Sexual Desire Screener. The primary outcome of interest was the report of any sexual dysfunction and urinary symptoms.

RESULTS

There were 531 total participants of 600 who completed the survey in its entirety. The mean age of the cohort was 29.6 ± 7.1 years, the majority were non-Hispanic White (76.6%). It was found that 55% of the women (n = 292) reported postpartum UI (73% [n = 213] stress incontinence, 26.7% [n = 78] urgency incontinence, and 0.003% [n = 1] mixed incontinence). Sexual dysfunction was more likely to be reported in participants with UI compared with those without UI (34.2% vs 17.8%, P < 0.001). Urinary incontinence was found to be associated with any form of sexual dysfunction after adjustment for confounders (adjusted odds ratio [aOR], 1.63; 95% confidence interval [CI], 1.07-2.14). Additional variables that were correlated with sexual dysfunction were perceived difficulty healing after any delivery injury (aOR, 4.79; 95% CI, 1.11-20.72), current breastfeeding (aOR, 3.29; 95% CI, 1.26-8.59), and an increasing Generalized Anxiety Disorder-7 score (aOR, 1.10 per 1-point increase; 95% CI, 1.05-1.15).

CONCLUSION

Urinary incontinence is independently associated with sexual dysfunction and should be systematically evaluated during postpartum care.

The effect of the birth method on changes of the prepartum and postpartum dimensions of perineal body

OBJECTIVE

The perineal body is critical for maintaining the integrity of the pelvic floor, especially in females as it can be injured during vaginal delivery. This study aimed to evaluate the effect of childbirth on perineal body dimensions by using a transperineal 2D ultrasound.

STUDY DESIGN

This prospective cohort study was performed in a tertiary obstetric care center. A total of 172 term pregnant women who delivered either by cesarean section or vaginal delivery were enrolled in the study. All demographic data and information were collected prospectively. The perineal body was measured in length, height, perimeter, and area. Mode of delivery was classified into four categories, including prelabor cesarean section, cesarean section during the first stage of labor, the first vaginal delivery, and more than one previously vaginal delivery. A postpartum evaluation was performed after 6 weeks.

RESULTS

Among the 172 women, 40 (23.3 %) had a history of cesarean section (CS) and they delivered with scheduled CS, 40 (23.3 %) women delivered by primary CS during active labor, 48 (27.9 %) women had the first vaginal delivery, 44 (25.6 %) women who delivered vaginally had a history of at least one vaginal delivery. The postpartum perineal body measurements were significantly lower in terms of length, perimeter, and area in all pregnancy groups.

CONCLUSION

Pregnancy and delivery change perineal body dimensions, significantly. Cesarean section does not completely protect against changes in perineal body morphology.

In vivo assessment of the elastic properties of women's pelvic floor during pregnancy using shear wave elastography: design and protocol of the ELASTOPELV study

Background

Animal studies have reported an increase in pelvic floor muscle stiffness during pregnancy, which might be a protective process against perineal trauma at delivery. Our main objective is to describe the changes in the elastic properties of the pelvic floor muscles (levator ani, external anal sphincter) during human pregnancy using shear wave elastography (SWE) technology. Secondary objectives are as follows: i) to look for specific changes of the pelvic floor muscles compared to peripheral muscles; ii) to determine whether an association between the elastic properties of the levator ani and perineal clinical and B-mode ultrasound measures exists; and iii) to provide explorative data about an association between pelvic floor muscle characteristics and the risk of perineal tears.

Methods

Our prospective monocentric study will involve three visits (14–18, 24–28, and 34–38 weeks of pregnancy) and include nulliparous women older than 18 years, with a normal pregnancy and a body mass index (BMI) lower than 35 kg.m^− 2. Each visit will consist of a clinical pelvic floor assessment (using the Pelvic Organ Prolapse Quantification system), an ultrasound perineal measure of the anteroposterior hiatal diameter and SWE assessment of the levator ani and the external anal sphincter muscles (at rest, during the Valsalva maneuver and during pelvic floor contraction), and SWE assessment of both the biceps brachii and the gastrocnemius medialis (at rest, extension and contraction). We will collect data about the mode of delivery and the occurrence of perineal tears. We will investigate changes in continuous variables collected using the Friedman test. We will look for an association between the elastic properties of the levator ani muscle and clinical / ultrasound measures using a Spearman test at each trimester. We will investigate the association between the elastic properties of the pelvic floor muscles and perineal tear occurrence using a multivariate analysis with logistic regression.

Discussion

This study will provide original in vivo human data about the biomechanical changes of pregnant women’s pelvic floor. The results may lead to an individualized risk assessment of perineal trauma at childbirth.

Trial registration

This study was registered on https://clinicaltrials.gov on July 26, 2018 (NCT03602196).

Effect of sexual health education on sexual function and resumption of sexual intercourse after childbirth in primiparous women

INTRODUCTION

A large number of women experience sexual health problems during the postpartum period. This study aimed to evaluate the effect of sexual health education on sexual function and time of sexual intercourse resumption after childbirth in primiparous women in Southeast Iran.

MATERIALS AND METHODS

This randomized clinical trial was conducted on 94 primiparous women randomly divided into two groups of intervention and control. The intervention group was subjected to three training sessions 3-5, 10-14, and 30-45 days after childbirth (first session lasting 20 min and other sessions 60 min). On the other hand, the participants in the control group only received the routine postpartum training. The Female Sexual Function Index (FSFI) was completed by all participants before and 8 weeks after the intervention. Data were analyzed in SPSS software (version 22) using descriptive and inferential statistics, such as Chi-square test, independent t-test, and paired sample t-test. P < 0.05 was considered statistically significant.

RESULTS

The mean score of FSFI in the intervention group was increased from 12.70 ± 6.166 before the onset of the intervention to 17.36 ± 5.407 after 8 weeks (P = 0.01). In the control group, the mean score of FSFI was decreased from 13.09 ± 4.306 to 12.29 ± 3.511 on the 8th week postpartum (P = 0.06). The mean times of sexual intercourse resumption in the intervention and control groups were 5.82 ± 0.17 and 5.81 ± 0.22 weeks, respectively, which were not significantly different between the two groups (P = 0.879).

CONCLUSION

Sexual health education for women in the postpartum period could improve their sexual function after childbirth. However, it is recommended to use sexual health education programs in women during the postpartum period to promote female sexual function.

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.

Tissue biomechanical behavior should be considered in the risk assessment of perineal trauma at childbirth

Perineal trauma at childbirth is associated with strong negative impacts on a woman's health but remains unpredictable. Pregnancy induces several changes in biomechanical behavior in humans as in animals, namely, an increase in ligamentous laxity and an increase in vaginal distensibility. Pelvic floor muscles in rats are reported to exhibit specific behaviors during pregnancy. Increases in both stiffness and the number of sarcomeres in series are observed and might process that protect against perineal trauma at childbirth. Some data in humans have shown that the risk of perineal trauma is highly linked to the intrinsic characteristics of the tissue, suggesting the potential benefit of incorporating intrinsic biomechanical characteristics in the risk prediction for perineal trauma. Shear wave elastography might be a useful noninvasive tool to investigate the elastic properties of these tissues in pregnant women in vivo, with the goal of implementing these properties as a predictive strategy.

Factors Influencing Couples' Sexuality in the Puerperium: A Systematic Review

INTRODUCTION

The puerperium is a period of adaptation in which various transformations take place in the lives of women and men on their way to becoming mothers and fathers. These changes can also have repercussions on their sexual relations. How the couple deals with this transition is crucial to the well-being of the couple and affects how parents relate to the baby.

AIM

This study aimed to explore the factors that influence sexuality in both women and men during postpartum.

METHODS

We conducted a bibliographic review of 236 articles found on the PubMed database and published from 2008 to January 2019.

MAIN OUTCOME MEASURE

The main outcome measure was the impact of various physical, psychological, and sociocultural factors on couples' sexual functioning during postpartum.

RESULTS

The main problems that couples face after childbirth can be classified as (i) psychological changes, such as loss of a sense of self, transitioning to parenthood, taking on the new roles of mother and father, and feelings of abandonment among men; (ii) body changes in women that affect their self-image and perineal trauma; (iii) hormonal changes in women and men that can lead to reduced sexual desire in both and vaginal dryness or dyspareunia in women; (iv) changes in the marital relationship, including changes in each other's roles, taking time for intimacy, and initiating sexual intercourse; (v) sociocultural influences, such as social support, culturally expected roles, and beliefs regarding when to resume sex; and (vi) lifestyle changes, especially with regard to baby care.

CONCLUSION

Sexuality during postpartum is influenced by multiple factors: physical, psychological, and sociocultural. Our findings offer a deeper understanding of how the transition to parenthood affects sexual relationships during the postpartum period. Implications regarding caring for and promoting the sexual health of individuals and couples after childbirth are discussed, and some medical recommendations for parents are offered. Serrano Drozdowskyj E, Gimeno Castro E, Trigo López E, et al. Factors Influencing Couples' Sexuality in the Puerperium: A Systematic Review. Sex Med Rev 2020;8:38-47.

Fetal head position and perineal distension associated with the use of the BD Odon Device™ in operative vaginal birth: a simulation study

Objective

To investigate (i) the placement of the BD Odon Device on the model fetal head, and (ii) perineal distention during simulated operative vaginal births conducted with the BD Odon Device

Design

Observational simulation study

Setting

North Bristol NHS Trust, UK

Population or Sample

440 simulated operative vaginal births

Methods

Three bespoke fetal mannequins were developed to represent (i) bi-parietal diameter of the 50^th centile at term (ii) bi-parietal diameter at the 5^th centile at term and (iii) 50^th centile head with 2 cm of caput. Siting of the BD Odon Device on model heads was determined before and after 400 simulated operative vaginal births. Variables were analysed to determine their effect on device siting and movement during birth.

The fetal mannequins were placed inside a maternal mannequin (PROMPT Flex, Limbs & Things, Bristol, UK) and the BD Odon Device was placed around the fetal head as per the instructions for use. The location of the air cuff was determined before and after the head was delivered. Perineal distension was determined by recording maximum perineal distention during a simulated operative vaginal birth using the same procedure, as well as scenarios employing an inappropriately non-deflated air cuff (for the BD Odon Device), the Kiwi ventouse and non-rotational forceps.

Main Outcome Measures

Site and displacement during birth of the BD Odon Device on a model head. Maximal perineal distension during birth.

Results

The BD Odon Device was reliably sited in a standard over the fetal head position (approximately 40mm above the fetal chin) for all stations, head sizes and positions with no significant displacement. In occipito-posterior births, compared to occipito-anterior or transverse, the BD Odon Device routinely sited further down the fetal head (toward the chin).

The BD Odon Device was not associated with more perineal distension than forceps or Kiwi ventouse (21mm vs 26mm vs 21mm at posterior fourchette).

Conclusions

The BD Odon Device reliably sited over a safe area of the fetal head in 400 simulated births representative of clinical practice. The BD Odon Device generates similar levels of perineal distension compared to Kiwi ventouse when used correctly.

[Childbirth pelvic floor trauma: Anatomy, physiology, pathophysiology and special situations - CNGOF perineal prevention and protection in obstetrics guidelines]

OBJECTIVES

To assess whether pelvic size and shape, spinal curvature, perineal body length and genital hiatus size are associated with the incidence of childbirth pelvic floor trauma. Special situations, such as obesity, ethnicity and hyperlaxity, will also be studied.

METHODS

A bibliographic research using Pubmed and Cochrane Library databases was conducted until May 2018. Publications in English and French were selected by initial reading of the abstracts. Randomized trials, meta-analyzes, case-control studies and large cohorts were studied in a privileged way.

RESULTS

A pubic arch angle<90° (measured clinically) does not appear to increase the risk of OASIS (Level 3), but appears to be a risk factor for postnatal anal incontinence at short-term, but not at long-term (Level 3). Measurement of pelvic dimensions and the subpubic angle is not recommended to predict OASIS or to choose the mode of delivery for the purpose of protecting the perineum (GradeC). Prenatal measurement of both perineal body (Level 3) and genital hiatus (Level 2) does not predict the incidence of 2nd or 3rd degree OASIS. Therefore, the routine prenatal measurement of the length of the perineal body or the genital hiatus is not recommended for any objective related to perineal protection (Grade C). Levator avulsion, resulting in a widening of the genital hiatus, is potentially a source of long-term pelvic floor dysfunction. Biomechanical models suggest that performing a mediolateral episiotomy and applying the fingers to the posterior perineum at the time of expulsive phase may reduce pelvic floor trauma. Obese women have a longer perineal body (Level 3), and obesity does not seem to increase the risk of OASIS (Level 2). There is no difference between Asian and non-Asian women perineal body (Level 3). No studies have validated that the liberal practice of episiotomy in Asian women reduced the risk of OASIS. It is therefore not recommended to practice an episiotomy for simple ethnic reasons in Asian women (GradeC). Compared to white women, black women do not appear to have an increased risk of OASIS and even appear to have a decreased risk of perineal tears of all stages (Level 2). Ligament hyperlaxity seems to be associated with an increased risk of OASIS (Level 2).

CONCLUSIONS

Prenatal assessment of pelvis bone, spine curvature, perineal body and genital hiatus do not allow to predict the incidence of childbirth pelvic floor trauma. Obesity and ethnicity are not risk factors for OASIS.

[Fetal expulsion: Which interventions for perineal prevention? CNGOF Perineal Prevention and Protection in Obstetrics Guidelines]

OBJECTIVE

The objective for all obstetricians and midwifes who intervene during the release of the fetal presentation is to prevent at best the perineal lesions. This work consisted in analyzing the literature, researching and evaluating interventions that reduce this perineal risk during the release.

METHODS

A keyword search for each medical intervention during the expulsion phase was conducted by selecting studies assessing perineal risk. Interventions during pregnancy and during delivery before the expulsion phase were specifically addressed in other sections of the recommendations.

RESULTS

Firstly, the degree of perineal stretching during the second stage of labour does not appear to be a risk factor for OASIS, postpartum incontinence, or sexual disorders (LE3) and that a substantial stretching of the perineum is not an indication of episiotomy (Professional consensus). Then, manual control of the expulsion of the fetus at the end of the second stage of labour and support of the posterior perineum during this time appear to reduce the rate of OASIS (LE3). The crowning of the baby's head should be manually controlled and the posterior perineum manually supported manually to reduce the risk of OASIS (GradeC). There is no recognised benefit to episiotomy in normal deliveries (LE1); the liberal practice of episiotomy results in fewer intact perineums than its restrictive practice, and the latter does not result in increasing the number of cases of OASIS. No evidence indicates that an episiotomy for women with a breech presentation, twin pregnancy, or posterior position prevents OASIS (LE3). Indication for episiotomy during delivery depends on individual risk factors and obstetric conditions (Professional consensus). It is recommended that the indication for episiotomy be explained and the woman's consent received before its performance. The performance of an episiotomy during normal deliveries is not recommended to reduce the risk of OASIS (Grade A). The liberal practice of episiotomy to prevent OASIS is not recommended for women with a breech presentation, twin pregnancy, or posterior position (GradeC). Episiotomy during an instrumental delivery appears to be associated with a reduction of the risk of OASIS (LE3). The vacuum extractor appears to induce fewer cases of OASIS than other instruments (LE3). Episiotomy may be indicated in instrumental deliveries to avoid OASIS (GradeC). Training in perineal protection in obstetrics is recommended (Grade B). In operative vaginal deliveries when several instruments can be used, a vacuum extractor is preferentially recommended to reduce the risk of OASIS (GradeC). When forceps or spatulas are used, it is preferable that they be withdrawn just before cephalic deflexion so that the fetal head is not "capped" with these instruments at birth (Professional consensus). Couder's maneuver, which consists of lowering the forearm during the release of the fetal shoulders, appears to decrease the rate of second-degree perineal tears and increase the rate of intact perineum (LE3).

CONCLUSION

Manual control of the expulsion and perineal support reduce the risk of perineal injury. There is no benefit to episiotomy in normal delivery, nor in special cases such the breech presentation for example. On the other hand, in case of instrumental delivery, an episiotomy may be indicated to avoid OASIS (GradeC), and it is recommended if it is possible to use the ventouse preferentially. The Couder's maneuver seems to reduce the rate of 2^nd degree perineal lesions (LE3). Finally, training in perineal obstetric protection is recommended (Grade B).

Association between pelvic floor dysfunction, and clinical and ultrasonographic evaluation in primiparous women: a cross-sectional study

PURPOSE

Disorders related to pelvic floor include urinary incontinence (UI), anal incontinence, pelvic organ prolapse, sexual dysfunction and pelvic pain. Because pelvic floor dysfunctions (PFD) can be diagnosed clinically, imaging techniques serve as auxiliary tools for establishing an accurate diagnosis. The objective is to evaluate the PFD in primiparous women after vaginal delivery and the association between clinical examination and three-dimensional ultrasonography (3DUS).

METHODS

A cross-sectional study was conducted in a in tertiary maternity. All primiparous women with vaginal deliveries that occurred between January 2013 and December 2015 were invited. Women who attended the invitation underwent detailed anamnesis, questionnaire application, physical examination and endovaginal and endoanal 3DUS. Crude and adjusted predictor factors for PFD were analyzed.

RESULTS

Fifty women were evaluated. Sexual dysfunction was the most prevalent PFD (64.6%). When associated with clinical features and PFD, oxytocin use increased by approximately four times the odds of UI (crude OR 4.182, 95% CI 1.149-15.219). During the multivariate analysis, the odds of UI were increased in forceps use by approximately 11 times (adjusted OR 11.552, 95% CI 11.155-115.577). When the clinical and obstetrical predictors for PFD were associated with 3DUS, forceps increased the odds of lesion of the pubovisceral muscle and anal sphincter diagnosed by 3DUS by sixfold (crude OR 6.000, 95% CI 1.172-30.725), and in multivariate analysis forceps again increased the odds of injury by approximately 7 times (adjusted OR 7.778, 95% CI 1.380-43.846).

CONCLUSION

Sexual dysfunction was the most frequent PFD. The use of forceps in primiparous women was associated with a greater chance of UI and pelvic floor muscle damage diagnosed by 3DUS.

Is increased peripheral ligamentous laxity in term pregnant women associated with obstetric anal sphincter injury?

INTRODUCTION AND HYPOTHESIS

Increased ligamentous laxity is associated with pelvic floor distension in pregnant women. This considered, it may also be related to the risk of obstetric anal sphincter injury (OASI). Our objective was to assess the association among increased ligamentous laxity, perineal tear severity, and OASI occurrence.

METHODS

This is a prospective study. We assessed ligamentous laxity between the 36th week of pregnancy and the onset of labor, by measuring the passive extension of the nondominant index finger for a 0.26 N.m torque applied to the second metacarpophalangeal joint (MCP laxity). We collected perineal tear occurrence and classification (Royal College of Obstetricians and Gynecologists). We investigated the MCP laxity distribution according to the stage of perineal tears, and then we looked for a predictive level of MCP laxity for OASI.

RESULTS

A total of 272 of the 300 pregnant women included had a vaginal delivery and were considered for the analysis. Mean age was 29 years, mean body mass index was 24.5 kg/m² and 39.2% of women were nulliparous. We reported 12 cases of OASI. MCP laxity significantly increased with the stage of perineal tears from 58° in stage 0 to 69° and 66° for stages 3a and 3b respectively. An MCP laxity higher than 64° was associated with OASI with sensitivity of 75%, specificity of 56%, and an area under the curve of 0.65.

CONCLUSION

Increased ligamentous laxity seems associated with OASI occurrence, which is the opposite of the initial hypothesis. This suggests that the stiffest tissues might be at a lower risk of injury.

Maternal Body Mass Index and Anovaginal Distance in Active Phase of Term Labor

Introduction

To evaluate if there was a difference in the anovaginal distance (AVD) measured by transperineal ultrasound between obese and normal weight women.

Material and Methods

A prospective observational study including 207 primiparous women at term in first stage of labor. Transperineal ultrasound with a vaginal probe was used to measure the AVD. Maternal, pregnancy, and delivery characteristics potentially associated with perineal thickness were extracted from woman's medical records. The participants were divided into three BMI groups based on maternal weight in early pregnancy: normal weight (BMI < 25), overweight (BMI 25–29.9), and obesity (BMI ≥ 30). Obese and overweight women were compared with normal weight women regarding the AVD.

Results

The mean AVD was 24.3, 24.9, and 27.0 mm in the normal weight, overweight, and obesity group, respectively. There were no group differences in background characteristics. The AVD was significantly longer in obese women compared with normal weight women (p = 0.018).

Conclusions

The observed longer AVD in obese women might be protective of the anal sphincter complex, explaining lower rates of anal sphincter injuries in this group. Further studies are indicated to evaluate whether the length of the AVD plays a role in the risk assessment of obstetric anal sphincter injury. The trial is registered in ClinicalTrials.gov and the trial registration ID is NCT03149965.