Ultrasound evaluation of the Cesarean scar: relation between a niche and postmenstrual spotting

A prospective study on risk factors associated with the development of isthmocele after caesarean section

OBJECTIVES

The primary objective was to detect the number of women developing isthmocele following lower segment caesarean section. The secondary objectives included analysing the risk factors associated with developing isthmocele and measuring the agreement between Transvaginal Ultrasonography (TVS) and Saline infusion Sonohysterography (SIS) in diagnosing Isthmocele.

METHODS

This study was conducted in the Department of Obstetrics and Gynecology and focused on women who had undergone Lower Segment cesarean Section (LSCS). The study aimed to detect any indentation of at least 2 mm in the scar site, known as isthmocele, using Transvaginal Ultrasound (TVS) and Saline Infusion Sonography (SIS) between 6 weeks and 6 months after delivery. Along with the primary objective, the study also evaluated several secondary outcomes such as maternal comorbidities, closure techniques, and labor details. The evaluation of isthmocele followed the 2019 modified Delphi consensus approach.

RESULTS

In our study, we found that 30% of our study population had isthmocele. We also observed that the number of previous caesarean deliveries, maternal BMI, duration of surgery, and characteristics of the previous CD scar were significantly associated with the development of isthmocele. When we compared the diagnostic methods, we found that TVS and SIS had similar limits of agreement for clinically important isthmocele parameters. However, we noticed a difference in the length and distance of isthmocele from the internal os, which we observed through Bland Altman plots.

CONCLUSION

Our research has shown that women who have undergone multiple caesarean deliveries, have a higher maternal body mass index (BMI), and experienced longer surgery duration are at a significantly higher risk of developing isthmocele. To prevent its development, it is recommended to promote vaginal birth after caesarean delivery whenever feasible, manage maternal obesity early on, and provide adequate surgical training to medical professionals. Additionally, transvaginal ultrasound (TVS) is an effective method for detecting isthmocele and can be used interchangeably with saline-infused sonography (SIS).

Single-layer vs double-layer uterine closure during cesarean delivery: 3-year follow-up of a randomized controlled trial (2Close study)

BACKGROUND

The rising rate of cesarean deliveries has led to an increased incidence of long long-term complications, including niche formation in the uterine scar. Niche development is associated with various gynecologic complaints and complications in subsequent pregnancies, such as uterine rupture and placenta accreta spectrum disorders. Although uterine closure technique is considered a potential risk factor for niche development, consensus on the optimal technique remains elusive.

OBJECTIVE

We aimed to evaluate the effect of single-layer vs double-layer closure of the uterine incision on live birth rate at a 3-year follow-up with secondary objectives focusing on gynecologic, fertility, and obstetrical outcomes at the same follow-up.

STUDY DESIGN

A multicenter, double-blind, randomized controlled trial was performed at 32 hospitals in the Netherlands. Women ≥18 years old undergoing a first cesarean delivery were randomly assigned (1:1) to receive either single-layer or double-layer closure of the uterine incision. The primary outcome of the long-term follow-up was the live birth rate; with secondary outcomes, including pregnancy rate, the need for fertility treatment, mode of delivery, and obstetrical and gynecologic complications. This trial is registered on the International Clinical Trials Registry Platform www.who.int (NTR5480; trial finished).

RESULTS

Between 2016 and 2018, the 2Close study randomly assigned 2292 women, with 830 of 1144 and 818 of 1148 responding to the 3-year questionnaire in the single-layer and double-layer closure. No differences were observed in live birth rates; also there were no differences in pregnancy rate, need for fertility treatments, mode of delivery, or uterine ruptures in subsequent pregnancies. High rates of gynecologic symptoms, including spotting (30%-32%), dysmenorrhea (47%-49%), and sexual dysfunction (Female Sexual Function Index score, 23) are reported in both groups.

CONCLUSION

The study did not demonstrate the superiority of double-layer closure over single-layer closure in terms of reproductive outcomes after a first cesarean delivery. This challenges the current recommendation favoring double-layer closure, and we propose that surgeons can choose their preferred technique. Furthermore, the high risk of gynecologic symptoms after a cesarean delivery should be discussed with patients.

Contrast Hysterosonographic Evaluation of Niche Prevalence Following a Standardized Suturing Technique for Caesarean Sections

Introduction

After caesarean section a uterine niche can be detected in 42-84% of all women and in 11-45% large defects with a residual myometrium < 2.2 mm occur. If the niche compromises > 50% of myometrial thickness, risk of uterine rupture during birth increases. The suturing technique might contribute substantially on pathogenesis of niches. The objective of this study is to investigate the effect of the suturing technique on niche prevalence by using a standardized two-layer surgical technique.

Methods

Women with one previous caesarean section were examined within 6-23 months after caesarean section using contrast medium-supported transvaginal sonography regarding the prevalence, sonomorphological aspect and clinical symptoms of a uterine niche. The surgical technique used was: dilatation of the cervix, interrupted suture of the first layer (excluding the endometrium), continuous closure of the visceral and parietal peritoneum.

Results

Using native vaginal sonography, no niches were visible in the whole cohort. In three cases, there was a small niche detectable with a depth between 2.3 and 3.9 mm by contrast hysterosonography. Regarding the total myometrial thickness, the niche depth compromised less than 50%. All patients were symptom-free.

Conclusion

In our study population, there were only three cases (9.1%) with a small uterine niche. Residual myometrium and niche percentage on myometrial thickness were excellent in all three cases. Thus, our results show that the uterotomy closure technique used in the study cohort might be superior with respect to the development of uterine niches compared with the expected prevalence.

Association of caesarean scar defect with risk of abnormal uterine bleeding: results from meta-analysis

OBJECTIVE

To investigate the association between caesarean scar defects and abnormal uterine bleeding through systematic literature review.

METHODS

PubMed, Web of Science, Cochrane Library and Embase databases were searched based on PRISMA 2020 to include studies exploring abnormal uterine bleeding in women with caesarean scar defects. The combined relative risk (RR) of uterine bleeding, combined prevalence of abnormal uterine bleeding and combined RR of intermenstrual uterine bleeding were calculated using a fixed- or random-effects model.

RESULTS

Ten studies involving 1,183 women with caesarean scar defects met the inclusion criteria for this study. Compared with women without caesarean scar defects, those with caesarean scar defects had a higher risk of abnormal uterine bleeding (RR: 3.22, 95% CI: 1.83-5.66) and intermenstrual bleeding (RR: 2.93, 95% CI: 1.91-4.50). The prevalence of abnormal uterine bleeding was approximately 0.46 (95% CI: 0.27-0.64), and across populations, women with a previous caesarean section who had undergone imaging specifically for gynaecological disease had a significantly higher prevalence of abnormal uterine bleeding (0.77, 95% CI: 0.65-0.89) than those with at least one caesarean Sect. (0.25, 95% CI: 0.10-0.39).

CONCLUSION

A significant association was observed between caesarean scar defects and abnormal uterine bleeding, with the former being a risk factor for the latter. However, previous studies have differed in the definition of caesarean scar defects and abnormal uterine bleeding, and more high-quality studies are needed to further investigate the relevant definitions and study results in the future.

Looking back to look forward: Has the time arrived for active management of obstetricians in placenta accreta spectrum?

Placenta accreta spectrum (PAS) is a relatively new obstetric condition which, until recently, was poorly understood. The true incidence is unknown because of the poor quality and heterogeneous diagnostic criteria. Classification systems have attempted to provide clarity on how to grade and diagnose PAS, but these are no longer reflective of our current understanding of PAS. This is particularly true for placenta percreta, which referred to extrauterine disease, as recent studies have demonstrated that placental villi associated with PAS have minimal potential to invade beyond the uterine serosa. It is accepted that PAS is a direct consequence of previous iatrogenic uterine injury, most commonly a previous cesarean section. Here, we "look back to look forwards"-starting with the primary predisposing factor for PAS, an iatrogenic uterine injury and subsequent wound healing. We then consider the evolution of definitions and diagnostic criteria of PAS from its first description over a century ago to current classifications. Finally, we discuss why modifications to the current classifications are needed to allow accurate diagnosis of this rare but life-threatening complication, while avoiding overdiagnosis and potential patient harm.

Hysteroscopic Management of Symptomatic Cesarean Scar Diverticulum in Patients Undergoing Frozen-Thawed Embryo Transfer: Impact on Clinical Pregnancy Rates and Pregnancy Complications

This retrospective cohort study aimed to compare the clinical outcomes of patients with cesarean scar defect (CSD) undergoing frozen embryo transfer (FET) with or without hysteroscopic repair surgery. The study included 82 patients, with 48 patients in surgical group A (undergoing CSD repair) and 34 patients in surgical group B (undergoing hysteroscopic treatment for other uterine lesions). The results showed that patients in group A had a larger CSD volume and a different shape compared to group B. However, there was no significant difference in clinical pregnancy rates between the two groups. Additionally, there were no differences in miscarriage, live birth, or preterm birth rates, and no complications such as scar pregnancy or placental abnormalities were observed in either group. These findings suggest that hysteroscopic treatment of CSD in symptomatic patients undergoing FET does not increase the risk of pregnancy complications and can lead to comparable clinical pregnancy rates with asymptomatic patients. Further studies with larger sample sizes are needed to confirm these results and evaluate long-term reproductive outcomes following CSD repair.

A common problem between gynecology, obstetrics, and reproductive medicine: Cesarean section scar defect

Approximately 60% of patients undergoing Cesarean sections may develop Cesarean Scar Defect (CSD), presenting a significant clinical challenge amidst the increasing Cesarean section rates. This condition, marked by a notch in the anterior uterine wall, has evolved as a notable topic in gynecological research. The multifactorial origins of CSD can be broadly classified into labor-related factors, patients' physical conditions, and surgical quality. However, conflicting influences of certain factors across studies make it challenging to determine effective preventive strategies. Additionally, CSD manifests with diverse symptoms, such as abnormal uterine bleeding, dysmenorrhea, chronic pelvic pain, dyspareunia, secondary infertility, and Cesarean scar pregnancy. Some symptoms are often attributed to other diagnoses, leading to delayed treatment. The quandary of when and how to manage CSD also adds to the complexity. Despite the development of various therapies, clear indications and optimal methods for specific conditions remain elusive. This longstanding challenge has troubled clinicians in both identifying and addressing this iatrogenic disease. Recent studies have yielded some compelling consensuses on various aspects of CSD. This review aims to consolidate the current literature on every facet of CSD. We hope to raise awareness among clinicians about this clinical problem, encouraging more relevant research to unveil the complete picture of CSD.

The association between gynecological complaints and the uterine sonographic features in women with a history of cesarean section

PURPOSE

The aim of this study is to investigate the association between post-cesarean sonographic uterine measures, dysmenorrhea, and bleeding disorders.

METHODS

This is a cross-sectional study where 500 women with a history of only one cesarean section (CS) were recruited. A transvaginal transducer, GE RIC6-12-D was used for the acquisition of volumetric datasets 18 ± 7 months postpartum. Uterine length (UL), cervical length (CL), niche length (L), niche depth (D), niche width (W), fibrosis length (FL), fibrosis depth (FD), residual myometrial thickness (RMT), endometrial thickness (EM), scar to internal os distance (SO), anterior myometrial thickness superior (sAMT) and inferior (iAMT) to the scar, and the posterior myometrial thickness opposite the scar (PMT), superior (sPMT), and inferior to it (iPMT) were measured. Logistic regression with odds ratios (OR), 95% confidence intervals (CI) and ROC curves were utilized.

RESULTS

The proportion of patients with incident post-cesarean bleeding disorders and dysmenorrhoea was 36% (CI 32%, 40%) and 17% (CI 14%, 21%) respectively. Univariate logistic regression showed that only UL was associated with bleeding disorders [OR 1.04 (CI 1.01,10.7) p value 0.005], whereas dysmenorrhea was associated with RMT [OR 0.82 (CI 0.71,0.95) p value 0.008], SO [OR 0.91 (CI 0.86,0.98) p value 0.01], and RMT ratio [OR 0.98 (CI 0.97,0.99) p value 0.03]. Multivariate logistic regression for dysmenorrhoea including SO and RMT remains statistically significant with p values <0.05 and area under the curve of 0.66.

CONCLUSION

There is an association between sonographic appearance of CS scars and dysmenorrhoea. Nevertheless, the association is weak and other biological post-cesarean characteristics should be explored as potential causes.

Isthmoceles - Accuracy of imaging diagnosis and clinical correlation with histology: A prospective cohort study

Background

Isthmoceles are a growing clinical concern.

Objectives

To evaluate the accuracy of diagnosis of isthmoceles by imaging and to correlate the dimensions with clinical symptoms and histopathology.

Materials and Methods

Prospective study of women (n=60) with ≥1 C-section undergoing hysterectomy. Isthmoceles were measured by imaging before surgery and macroscopically on the specimen after hysterectomy, followed by histological analysis.

Main outcome measures

Accuracy of isthmocele diagnosis, correlation with clinical symptoms, and histopathological findings.

Result

By imaging, isthmoceles were slightly deeper (P=0.0176) and shorter (P=0.0045) than macroscopic measurements. Differences were typically small (≤3mm). Defined as an indentation of ≥2 mm at site of C-section scar, imaging diagnosed 2 isthmoceles consequently not seen by histology and missed 3. Number of prior C-sections increased isthmocele severity but neither the incidence nor the remaining myometrial thickness (RMT) did. Severity correlated positively with symptoms and histology. However, clinical use was limited. Histological analysis revealed presence of thick wall vessels in 100%, elastosis in 40%, and adenomyosis in 38%. Isthmocele lining was asynchronous with the menstrual phase in 31%.

Conclusions

Dimensions of isthmoceles by imaging were largely accurate with occasionally large differences observed. Number of C-sections did not increase isthmocele incidence, only severity. Indication for surgery remains clinical, considering dimensions and symptoms.

What is new?

Dimensions of isthmoceles should be confirmed before surgery since uterine contractions might change those dimensions. Symptoms increase with dimensions of isthmoceles but are not specific. Endometrial lining within the isthmocele can be asynchronous with the menstrual phase.

Effect of hysteroscopic surgery on IVF/ICSI pregnancy outcomes for different cesarean scar diverticulum severity: A retrospective cohort study

OBJECTIVE

To investigate associations between hysteroscopic surgery for patients with varying cesarean scar diverticulum (CSD) severity and in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) embryo transfer (ET) pregnancy outcomes, focusing also on the correlation between the CSD size with its severity, and pregnancy outcomes.

METHODS

A retrospective study was conducted on patients with CSD who underwent IVF/ICSI-ET at a university-based hospital between January 2017 and July 2023. Patients were categorized into four groups based on CSD severity and whether they received hysteroscopic surgery: a mild surgical group (Group A, n = 86), a mild non-surgical group (Group B, n = 30), a moderate-to-severe surgical group (Group C, n = 173), and a moderate-to-severe non-surgical group (Group D, n = 96). Baseline characteristics and pregnancy outcomes were compared among these groups. Correlation assessments were conducted to explore relationships between CSD size with its severity, and pregnancy outcomes.

RESULTS

Compared with Group D, Group C exhibited significantly increased rates of biochemical pregnancy (odds ratio [OR] 1.90; 95% confidence interval [CI] 1.03-3.51, P = 0.041), clinical pregnancy (OR 2.30; 95% CI1.18-4.45; P = 0.014), and live birth (OR 2.77; 95% CI 1.10-7.00, P = 0.031). However, no differences in pregnancy outcomes were observed between Groups A and B. Correlation analyses revealed significant positive associations between CSD severity and its depth, length, width, and volume.

CONCLUSIONS

Patients with moderate-to-severe CSD achieved favorable IVF/ICSI pregnancy outcomes following hysteroscopic surgery. The CSD size was significantly related to its severity.

The association of endometrial closure during cesarean section to the risk of developing uterine scar defect: a randomized control trial

PURPOSE

The surgical technique for uterine closure following cesarean section influences the healing of the cesarean scar; however, there is still no consensus on the optimal technique regarding the closure of the endometrium layer. The aim of this study was to compare the effect of closure versus non-closure of the endometrium during cesarean section on the risk to develop uterine scar defect and associated symptoms.

METHODS

A randomized prospective study was conducted of women undergoing first elective cesarean section at a single tertiary medical center. Exclusion criteria included previous uterine scar, preterm delivery and dysmorphic uterus. Women were randomized for endometrial layer closure versus non-closure. Six months following surgery, women were invited to the ambulatory gynecological clinic for follow-up visit. 2-D transvaginal ultrasound examination was performed to evaluate the cesarean scar characteristics. In addition, women were evaluated for symptoms that might be associated with uterine scar defect. Primary outcome was defined as the residual myometrial thickness (RMT) at the uterine cesarean scar. Data are presented as median and interquartile range.

RESULTS

130 women were recruited to the study, of them follow-up was achieved in 113 (86.9%). 61 (54%) vs. 52 (46%) of the women were included in the endometrial closure vs. non-closure groups, respectively. Groups were comparable for patient's demographic, clinical characteristics and follow-up time for postoperative evaluation. Median RMT was 5.3 (3.0-7.7) vs. 4.6 (3.0-6.5) mm for the endometrial closure and non-closure groups, respectively (p = 0.38). Substantially low RMT (< 2.5 mm) was measured in four (6.6%) women in the endometrial closure group and three (5.8%) of the women in the non-closure group (p = 0.86). All other uterine scar sonographic measurements, as well as dysmenorrhea, pelvic pain and intermenstrual bleeding rates were comparable between the groups.

CONCLUSION

Closure versus non-closure of the endometrial layer during cesarean uterine incision repair has no significant difference in cesarean scar characteristics and symptom rates at 6 months follow-up.

Effects of endometrial versus non-endometrial suturing on isthmocele development; a randomized controlled trial

OBJECTIVE

Incomplete healing after cesarean section (CS) can result in isthmocele formation. When suturing the uterus, fully folding the wound lips may embed the endometrial layer into the myometrium, leading to isthmocele development. Hence, this study aimed to compare the effects of endometrial and non-endometrial suturing on isthmocele development.

MATERIAL AND METHODS

This randomized controlled trial included 274 patients. Women who underwent primary CS were randomly allocated to one of the two study groups: endometrial suturing and non-endometrial suturing. The primary outcome was isthmocele rate at postpartum 6 months. Secondary outcomes were the volume of the isthmocele, thickness of the residual myometrium, menstrual irregularities (intermenstrual spotting), and the relationship between the isthmocele and uterine position.

RESULTS

A total of 159 patients (81 in the endometrial suturing group and 78 in the non-endometrial suturing group) were analyzed. The incidence of isthmocele was significantly lower in the non-endometrial suturing group than in the endometrial suturing group (12 [15.4%] vs. 24 [29.6%] patients; p = 0.032). Menstrual irregularities, such as intermenstrual spotting, were significantly higher in the endometrial suturing group than in the non-endometrial group (p = 0.019).

CONCLUSION

Uterine closure with non-endometrial suturing was associated with significantly lower isthmocele development and less intermenstrual spotting compared to that with endometrial suturing.

Isthmocele and Infertility

Isthmocele is a gynecological condition characterized by a disruption in the uterine scar, often associated with prior cesarean sections. This anatomical anomaly can be attributed to inadequate or insufficient healing of the uterine wall following a cesarean incision. It appears that isthmocele may impact a woman's quality of life as well as her reproductive capacity. The incidence of isthmocele can range from 20% to 70% in women who have undergone a cesarean section. This review aims to sum up the current knowledge about the effect of isthmocele on fertility and the possible therapeutic strategies to achieve pregnancy. However, currently, there is not sufficiently robust evidence to indicate the need for surgical correction in all asymptomatic patients seeking fertility. In cases where surgical correction of isthmocele is deemed necessary, it is advisable to evaluate residual myometrial thickness (RMT). For patients with RMT >2.5-3 mm, hysteroscopy appears to be the technique of choice. In cases where the residual tissue is lower, recourse to laparotomic, laparoscopic, or vaginal approaches is warranted.

A morphological study of symptomatic uterine niche using three-dimensional models from thin-slice magnetic resonance imaging

RESEARCH QUESTION

Is there a correlation between various morphological parameters of the uterine niche and post-menstrual spotting using three-dimensional models from thin-slice (1 mm) magnetic resonance imaging (MRI)?

DESIGN

This study retrospectively identified women diagnosed with a symptomatic niche by thin-slice MRI between December 2019 and December 2021. Univariable and multivariable linear regression models assessed the correlations between morphological parameters and the duration post-menstrual spotting. Morphological differences of the niche formed by one versus two Caesarean sections were analysed by univariable and multivariable logistic analysis.

RESULTS

A total of 205 women diagnosed with symptomatic niche were included in the study. The niche among most women with post-menstrual spotting was ellipsoidal, with width greater than length greater than depth, from which niche volume was estimated based on manual measurements (volume = 0.520 × length × width × depth). Manually calculated niche length (β = 0.257, 95% confidence interval [CI] 0.040-0.473, P = 0.020) and radiomically assessed minor axis length (β = 0.329, 95% CI 0.009-0.795, P = 0.045) both positively correlated with the duration of post-menstrual spotting, whereas the distance between the niche and external os (β = -0.120, 95% CI -0.202 to -0.038, P = 0.004) was inversely correlated. Women with two Cesarean sections reported more days of post-menstrual spotting (8.76 ± 3.54 versus 6.68 ± 3.90 days, P < 0.001) and had increased niche length diameter (adjusted odds ratio [aOR] 1.304, 95% CI 1.190-1.429) and a smaller surface-area-to-volume ratio (aOR 0.296, 95% CI 0.129-0.680).

CONCLUSIONS

Niche-associated post-menstrual spotting correlates with the length diameter of the niche and the distance between the niche and external os. Niches in women after two Caesarean sections tend to be longer in length diameter and more spherical.

Evaluation of Cesarean section scar using saline contrast sonohysterography in women with previous Cesarean scar pregnancy

OBJECTIVE

To evaluate Cesarean scar defects using saline contrast sonohysterography (SCSH) in women with a history of Cesarean scar pregnancy (CSP).

METHODS

A cohort of 38 non-pregnant women with a history of CSP treated with combined local and systemic methotrexate was investigated prospectively by SCSH. For the purpose of analysis, they were classified, according to the modified Delphi consensus criteria for CSP in early gestation, into three subgroups based on the depth of the gestational sac herniation in the midsagittal plane. Subgroup A included eight (21.1%) cases, in which the largest part of the gestational sac protruded towards the uterine cavity; Subgroup B included 20 (52.6%) cases, in which the largest part of the gestational sac was embedded in the myometrium; and Subgroup C included 10 (26.3%) cases, in which the gestational sac was located partially outside the outer contour of the cervix or uterus.

RESULTS

SCSH revealed that all women in Subgroup C had a uterine niche. The median niche length (P = 0.006) and depth (P = 0.015) were significantly greater in Subgroup C than in Subgroups A or B. The median residual myometrial thickness (RMT) was significantly lower in Subgroup C than in Subgroups A or B (P = 0.006).

CONCLUSIONS

Women with prior CSP who had a gestational sac protruding beyond the serosal line had a significantly greater niche length and depth, and lower RMT. This knowledge may guide individualized risk counseling. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Evaluation of Association Between Adenomyosis and Cesarean Scar Defect

PURPOSE

This study aims to investigate and compare quantitative factors of the cesarean scar defect (CSD) in symptomatic patients with and without uterine adenomyosis.

METHOD

This study was conducted as a case-control study. Patients who met the inclusion criteria were divided into two groups: with adenomyosis (case) and without adenomyosis (control). The demographic data, medical history, and sonohysterography findings were extracted from the patient's documents and archived images.

RESULT

During 2 years, 310 symptomatic women with a history of previous cesarean section underwent sonohysterography. Among them, 204 patients met the inclusion criteria. The most common chief complaints were post-menstrual bleeding (34.3%) and prolonged bleeding (27%). Cesarean scar depth and width significantly differed between these two groups, and patients with underlying adenomyosis had significantly larger defects (P-value of .009 and .005, respectively). Mean RMT/AMT ratio was 31.83% in the case group and 42.88% in the control group. In our study, RMT/AMT ratios were significantly lower in the case group (P-value of .001). In addition, we performed analysis on a subgroup of patients with one prior cesarean section. Similar results were achieved with a lower RMT/AMT ratio in case group (mean of 31.20% in case group and 46.47% in control group; P-value of .000).

CONCLUSION

Our study showed a strong association between the presence of adenomyosis and larger clinically more significant CSDs. To establish a causative relationship, we suggest a prospective cohort study to follow up the patients and compare the evolution of CSD in patients with and without adenomyosis.

Laparoscopic Correction of Isthmocele and Cesarean Scar Endometriosis: A Report of a Successful Pregnancy and Treatment of Subfertility

We present a case of subfertility due to isthmocele and cesarean scar endometriosis with a successful pregnancy following laparoscopic repair. This case report is of a 35-year-old female (para 1, living 1) who presented to the gynecological outpatient department with complaints of lower abdominal pain, irregular vaginal bleeding for three months, and subfertility. She was suspected to have isthmocele and endometriosis at the site of the cesarean scar with seroma formation. She underwent a hysteroscopy and laparoscopic excision of the cyst at the site of the cesarean scar with the repair of the cesarean scar defect. Diagnosis of scar endometriosis was confirmed on histopathology. She successfully became pregnant after one year and had a full-term pregnancy and delivered via cesarean section. Cesarean scar defect, also known as isthmocele, emerges as a notable complication following cesarean delivery, often linked with secondary infertility. Other associated complications of scar defect are prolonged menstrual bleeding, dysmenorrhea, dyspareunia, and chronic pelvic pain. The laparoscopic reparation of the uterine scar defect proves to be a successful approach in addressing secondary infertility and subfertility issues. Individuals with a prior cesarean section history, expressing concerns about secondary infertility and distressing complaints, require a thorough examination of the uterine scar before embarking on future pregnancy plans. Scar endometriosis is an uncommon medical condition and can worsen patient symptoms and lead to further complications. Diagnosis is often established following the excision of the lesion and subsequent histopathological examination. Prompt management can relieve patient symptoms and prevent further complications.

Diagnostic value of enhanced-contrast ultrasound for cesarean scar pregnancy: A systematic review

BACKGROUND

Cesarean scar pregnancy, an uncommon ectopic pregnancy in which the embryo is implanted in the cesarean scar, poses significant risks without prompt diagnosis and treatment. Its prevalence has risen alongside increased cesarean section rates. Despite various treatment approaches, consensus remains elusive. Ultrasonography, particularly contrast-enhanced ultrasonography, shows promise in cesarean scar pregnancy diagnosis.

MAIN BODY

This systematic review, following PRISMA guidelines, explores contrast-enhanced ultrasound's diagnostic potential in cesarean scar pregnancy. We searched PubMed, Scopus, Web of Science, and Google Scholar up to August 2023. Selection involved two stages: title/abstract screening and full-text assessment. The included studies investigated contrast-enhanced ultrasound's diagnostic value in cesarean scar pregnancy, provided adequate data, and were peer-reviewed in English. Quality assessment followed the QUADAS-2 criteria. We extracted the diagnostic accuracy metrics: sensitivity, specificity, and accuracy. Out of 193 records, five studies met the inclusion criteria (2016-2020, China). Contrast-enhanced ultrasound displayed sensitivities of 77%-100% and specificities of 95%-100%. Two studies reported accuracy of 96.9%-97.8%. Compared with conventional ultrasound, contrast-enhanced ultrasound exhibited superior sensitivity, specificity, and accuracy. It also outperformed transvaginal ultrasound.

CONCLUSION

Enhanced-contrast ultrasound holds promise for diagnosing and managing cesarean scar pregnancy by visualizing scar vascularization in real-time, thereby reducing severe complication risks. This review highlights contrast-enhanced ultrasound as a transformative diagnostic tool for cesarean scar pregnancy management, despite existing evidence limitations.

Reproductive outcomes after laparoscopic resection of symptomatic niches in uterine cesarean scars: Long-term follow-up on the prospective LAPNICHE study

INTRODUCTION

After incomplete healing of the uterine cesarean section scar, a niche can be observed; 24% of the women develop large niches with a residual myometrial thickness <3 mm. In these cases a laparoscopic resection is possible. The effect of this new treatment on fertility outcome is not known yet. This paper describes reproductive outcomes 2 years after a laparoscopic niche resection and compares women with or without secondary infertility at baseline.

MATERIAL AND METHODS

A prospective cohort study was performed, with consecutive inclusion of women between 2011 and 2019. Women with a niche in the uterine cesarean scar, with a residual myometrial thickness of <3 mm and with a desire to become pregnant, were scheduled to undergo a laparoscopic niche resection because of one or more of the following problems (1) postmenstrual spotting; (2) midcycle intrauterine fluid accumulation diagnosed during the fertility workup or (3) difficulties with a previous embryo transfer and preferring a surgical therapy. The study is registered in the ISRCTN register (ref. no. ISRCTN02271575) on April 23, 2013.

RESULTS

There were 133 (62%) women included with a desire to become pregnant, 88 with secondary infertility. In all, 83 had an ongoing pregnancy at the 2-year follow-up. The ongoing pregnancy rate in patients with previous fertility problems was 60.2% compared with 66.7% in patients without infertility (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.32-1.7). The OR for live births was 0.57 (95% CI 0.02-1.2). Overall, 8.3% of the pregnancies resulted in miscarriages by the 2-year follow-up.

CONCLUSIONS

The reproductive outcomes in women with and without previous fertility problems undergoing resection of a large niche are very promising and quite comparable in both groups. These results suggest, but do not prove, a beneficial effect of this therapy for these indications. The results support the design of future randomized controlled trials to evaluate the effect of niche resection vs expectant management to assess its additional value in women with or without fertility problems who desire pregnancy.

Diagnosis and management of isthmocele (Cesarean scar defect): a SWOT analysis

The purpose of this State-of-the-Art Review was to provide a strategic analysis, in terms of strengths, weaknesses, opportunities and threats (SWOT analysis), of the current evidence regarding the management of uterine isthmocele (Cesarean scar defect). Strengths include the fact that isthmocele can be diagnosed on two-dimensional transvaginal ultrasound, and that surgical repair may restore natural fertility potential and prevent secondary infertility, as well as reduce the risk of miscarriage and other obstetric complications. However, there is a lack of high-quality evidence regarding the best diagnostic method and criteria, as well as the potential benefits of surgical repair with respect to fertility. There is a need for experienced surgeons skilled in the various isthmocele repair techniques. Isthmocele repair does not prevent the need for Cesarean delivery in subsequent pregnancies. There is increasing awareness regarding the accuracy of transvaginal ultrasound in diagnosing isthmocele. This may lead to surgical correction and prevention of obstetric and perinatal complications in subsequent pregnancies, including Cesarean scar pregnancy. Regarding threats, the existence of different surgical techniques means that there is a risk of selecting an inadequate approach if the type of isthmocele and the patient's characteristics are not considered. There is a risk of overtreatment when asymptomatic defects are repaired surgically. Finally, there is an absence of cost-effectiveness analyses to justify routine repair. Thus, while there are many data suggesting that isthmocele has an adverse effect on both natural fertility and the outcome of assisted reproduction techniques, high-quality evidence to support surgical isthmocele repair in all asymptomatic patients desiring future fertility are lacking. There is increasing agreement to recommend hysteroscopic repair of isthmocele as a first-line approach as long as the residual myometrial thickness is at least 2.5-3.0 mm. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A large post-caesarean Niche (Isthmocele) with amenorrhea, a symptom that was not reported in the medical literature: A rare case report

INTRODUCTION AND IMPORTANCE

Isthmocele is identified as an iatrogenic defect in the myometrium of the anterior uterine wall at the site of a previous cesarean scar due to defective tissue healing. Patients may have varied symptoms including abnormal uterine bleeding (AUB) and pelvic pain. Herein, we report a rare case of a large isthmocele that manifested with secondary amenorrhea; which was not reported in the medical literature previously.

CASE PRESENTATION

A 30-year-old Syrian woman, G5P5, came to our clinic with a complaint of secondary amenorrhea that began two years ago. She was treated symptomatically with progesterone with no response. She has had five cesarean sections. Ultrasonography findings suggested a large uterine niche. Trans-Abdominal niche repair was the obtained technique, depending on the drainage of the isthmocele, excising the fibrotic tissue from the edges and re-approximating them. On follow-up, menstruation returned to normal.

CLINICAL DISCUSSION

Isthmocele can be, radiologically, defined as a hypoechoic or anechoic, triangular area at the scar site. Its pathophysiology is still unknown. Although, an isthmocele can be diagnosed using a variety of imaging techniques like ultrasonography (US), magnetic resonance imaging (MRI), sonohysterography, and hysteroscopy; transvaginal ultrasound (TVUS) is the first method described for assessing it. The goal of isthmocele treatment is to alleviate symptoms.

CONCLUSION

We recommend that health awareness campaigns alert people to the need to see a specialist doctor in the context of a serious complaint. For the uterine niche, many risk factors can be avoided to reduce its probability.

Cesarean scar disorder: Management and repair

Cesarean scar disorder (CSD) is an entity recently defined as uterine niche with at least one primary or 2 secondary symptoms. CSDs can be visualized by hysterosalpingography, transvaginal sonography, saline infusion sonohysterography, hysteroscopy, and magnetic resonance imaging, but diagnosis should be performed by exams able to measure the residual myometrial thickness (RMT). Although there is a limited number of studies evaluating fertility and reproductive outcomes after different types of surgery, the following consideration should be kept in mind. Asymptomatic women should not be operated with the hope of improving obstetrical outcomes. It is reasonable to consider hormone therapy for CSDs as a symptomatic treatment in women who no longer wish to conceive and have no contraindications. In case of failure of or contraindications to medical treatment, surgery should be offered according to the severity of symptoms, including infertility, the desire or otherwise to preserve the uterus, the size of the CSD, and RMT measurement. Hysteroscopy is considered to be more of a resection than a repair, so women who desire pregnancy should be excluded from this technique in case of RMT <3 mm. In this instance, repair is essential and can only be achieved by a laparoscopic or vaginal approach. The benefit of laparoscopic approach seems to persist after subsequent CS. Women with CSDs need to be given complete information, including available literature, before any treatment decision is made.

The definition, diagnosis, and symptoms of the uterine niche - A systematic review

Of all neonates, 21% are delivered by cesarean section (CS). A long-term maternal complication of an SC is a uterine niche. The aim of this review is to provide an overview of the current literature on imaging techniques and niche-related symptomatology. We performed systematic searches on imaging and niche symptoms. For both searches, 87 new studies were included. Niche evaluation by transvaginal sonography (TVS) or contrast sonohysterography (SHG) proved superior over hysteroscopy or magnetic resonance imaging. Studies that used SHG in a random population identified a niche prevalence of 42%-84%. Niche prevalence differed based on niche definition, symptomatology, and imaging technique. Most studies reported an association with gynecological symptoms, poor reproductive outcomes, obstetrical complications, and reduced quality of life. In conclusion, non-invasive TVS and SHG are the superior imaging modalities to diagnose a niche. Niches are prevalent and strongly associated with gynecological symptoms and poor reproductive outcomes.

The association between uterine scar defect (niche) and the presence of symptoms

RESEARCH QUESTION

Is there association between the presence of a uterine niche and the presence of symptoms?

DESIGN

This cross-sectional study was conducted at a single tertiary medical centre. All women who underwent Caesarean section from January 2017 to June 2020 were invited to the gynaecological clinics, and requested to complete a questionnaire regarding symptoms related to the presence of a niche (heavy menstrual bleeding, intermenstrual spotting, pelvic pain, infertility). Transvaginal two-dimensional ultrasonography was performed to assess the uterus and uterine scar characteristics. The primary outcome was defined as the presence of a uterine niche, evaluated by length, depth, residual myometrial thickness (RMT) and ratio between the residual myometrial thickness (RMT) and adjacent myometrial thickness (AMT).

RESULTS

Of 524 women who were eligible and scheduled for evaluation, 282 (54%) completed the follow-up; 173 (61.3%) were symptomatic and 109 (38.6%) asymptomatic. Niche measurements, including RMT/AMT ratio, were comparable between the groups. In a sub-analysis of each symptom, heavy menstrual bleeding and intermenstrual spotting were associated with reduced RMT (P = 0.02 and P = 0.04, respectively) compared with women with normal menstrual bleeding. An RMT less than 2.5 mm was significantly more prevalent in women reporting heavy menstrual bleeding (11 [25.6%] versus 27 [11.3%]; P = 0.01] and new infertility (7 [16.3%] versus 6 [2.5%]; P = 0.001]. In logistic regression analysis, infertility was the only symptom associated with an RMT less than 2.5 mm (B = 1.9; P = 0.002).

CONCLUSIONS

A reduced RMT was found to be associated with heavy menstrual bleeding and intermenstrual spotting, while values below 2.5 mm were also associated with infertility.

Effectiveness of laparoscopic niche resection versus expectant management in patients with unexplained infertility and a large uterine caesarean scar defect (uterine niche): protocol for a randomised controlled trial (the LAPRES study)

INTRODUCTION

A uterine niche is a defect at the site of the uterine caesarean scar that is associated with gynaecological symptoms and infertility. Promising results are reported in cohort studies after a laparoscopic niche resection concerning reduction of gynaecological symptoms in relation to baseline and concerning pregnancy outcomes. However, randomised controlled trials to study the effect of a laparoscopic niche resection on reproductive outcomes in infertile women are lacking. This study will answer the question if laparoscopic niche resection in comparison to expectant management improves reproductive outcomes in infertile women with a large uterine niche.

METHODS AND ANALYSIS

The LAPRES study is a randomised, non-blinded, controlled trial, including 200 infertile women with a total follow-up of 2 years. Women with the presence of a large niche in the uterine caesarean scar and unexplained infertility of at least 1 year or failed IVF will be randomly allocated to a laparoscopic niche resection within 6 weeks or to expectant management for at least 9 months. A large niche is defined as a niche with a depth of >50% of the myometrial thickness and a residual myometrium of ≤3 mm on transvaginal ultrasound. Those receiving expectant management will be allowed to receive fertility therapies, including assisted reproductive techniques, if indicated. The primary outcome is time to ongoing pregnancy, defined as a viable intrauterine pregnancy at 12 weeks' gestation. Secondary outcome measures are time to conception leading to a live birth, other pregnancy outcomes, received fertility therapies after randomisation, menstruation characteristics, patient satisfaction, quality of life, additional interventions, and surgical and ultrasound outcomes (intervention group). Questionnaires will be filled out at baseline, 6, 12 and 24 months after randomisation. Ultrasound evaluation will be performed at baseline and at 3 months after surgery.

ETHICS AND DISSEMINATION

The study protocol was approved by the medical ethics committee of the Amsterdam University Medical Centre. (Ref. No. 2017.030). Participants will sign a written informed consent before participation. The results of this study will be submitted to a peer-reviewed journal for publication. TRIAL REGISTRATION NUMBER DUTCH TRIAL REGISTER REF NO NL6350 : http://www.trialregister.nl.

Comparing levonorgestrel intrauterine system with hysteroscopic niche resection in women with postmenstrual spotting related to a niche in the uterine cesarean scar: a randomized, open-label, controlled trial

BACKGROUND

Postmenstrual spotting and chronic pelvic pain after cesarean delivery are associated with the presence of niches. Levonorgestrel intrauterine system (52 mg) and hysteroscopic niche resection have been shown to relieve niche-related symptoms at 6 months after the intervention.

OBJECTIVE

This trial aimed to compare the effectiveness of 52-mg levonorgestrel intrauterine system with that of hysteroscopic niche resection in reducing niche-related postmenstrual spotting.

STUDY DESIGN

This randomized, open-label, controlled trial was conducted at a medical center in Shanghai, China. Women with symptoms of postmenstrual spotting after cesarean delivery, with a niche depth of at least 2 mm and residual myometrium of at least 2.2 mm on magnetic resonance imaging, and no intention to conceive within the next year were randomly assigned to receive treatment with 52-mg levonorgestrel intrauterine system or hysteroscopic niche resection. The primary outcome was the reduction in postmenstrual spotting at 6 months after randomization, defined as the percentage of women with a reduction of at least 50% in spotting days relative to baseline. Efficacy and safety were assessed using intention-to-treat analysis.

RESULTS

Between September 2019 and January 2022, 208 women were randomized into the levonorgestrel intrauterine system group (N=104) or the hysteroscopic niche resection group (N=104). At the 6-month follow-up, a 50% reduction in spotting had occurred in 78.4% (80/102) of women in the levonorgestrel intrauterine system group and in 73.1% (76/104) of women in the hysteroscopic niche resection group (relative risk, 1.07 [95% confidence interval, 0.92-1.25]; P=.370). Spotting decreased over time (Ptrend=.001), with a stronger reduction observed in the levonorgestrel intrauterine system group (P=.001). There was also a significant interaction between time and treatment (P=.007). From 9 months onward, a more significant reduction in spotting was observed in the levonorgestrel intrauterine system group than in the hysteroscopic niche resection group (9 months, 89.2% vs 72.1%; relative risk, 1.24 [95% confidence interval, 1.08-1.42]; 12 months, 90.2% vs 70.2%; relative risk, 1.29 [95% confidence interval, 1.12-1.48]). Moreover, compared with the hysteroscopic niche resection group, the levonorgestrel intrauterine system group had significantly fewer postmenstrual spotting days and total bleeding days from 6 months onward (all P<.001), and less pelvic pain from 3 months onward (all P<.010). No intervention-related complications were reported in any group. During follow-up, 11 (10.8%) women reported hormone-related side effects, and 2 women (2.0%) in the levonorgestrel intrauterine system group had spontaneous partial expulsion. Meanwhile, 3 unintended pregnancies were reported in the hysteroscopic niche resection group.

CONCLUSION

In women with niche-related postmenstrual spotting, the levonorgestrel intrauterine system was not more effective than hysteroscopic niche resection in reducing the number of spotting days by at least 50% at 6 months. However, the levonorgestrel intrauterine system was superior in reducing spotting from 9 months onward, and it reduced the absolute number of spotting days from 6 months onward and pelvic pain from 3 months onward.

Outcomes of Laparoscopic Cesarean Scar Defect Repair: Retrospective and Observational Study

Cesarean scar defect, also known as niche, isthmocele, uteroperitoneal fistula and uterine diverticulum, is a known complication after cesarean delivery. Due to the rising cesarean delivery rates, niche has become more common and can present as irregular bleeding, pelvic pain, infertility, cesarean scar pregnancy and uterine rupture. Treatments for symptomatic cesarean scar defect vary and include hormonal therapy, hysteroscopic resection, vaginal or laparoscopic repair, and hysterectomy. We report on the safety and efficacy of our method of repairing cesarean scar defects in 27 patients without adverse outcomes: two-layer repair where the suture does not enter the uterine cavity. Our method of laparoscopic niche repair improves symptoms in nearly 77% of patients, restores fertility in 73% of patients, and decreases the time to conception.

Prognostic model on niche development after a first caesarean section: development and internal validation

OBJECTIVE

To develop and internally validate a prognostic prediction model for development of a niche in the uterine scar after a first caesarean section (CS).

STUDY DESIGN

Secondary analyses on data of a randomized controlled trial, performed in 32 hospitals in the Netherlands among women undergoing a first caesarean section. We used multivariable backward logistic regression. Missing data were handled using multiple imputation. Model performance was assessed by calibration and discrimination. Internal validation using bootstrapping techniques took place. The outcome was 'development of a niche in the uterus', defined as an indentation of ≥ 2 mm in the myometrium.

RESULTS

We developed two models to predict niche development: in the total population and after elective CS. Patient related risk factors were: gestational age, twin pregnancy and smoking, and surgery related risk factors were double-layer closure and less surgical experience. Multiparity and Vicryl suture material were protective factors. The prediction model in women undergoing elective CS revealed similar results. After internal validation, Nagelkerke R² ranged from 0.01 to 0.05 and was considered low; median area under the curve (AUC) ranged from 0.56 to 0.62, indicating failed to poor discriminative ability.

CONCLUSIONS

The model cannot be used to accurately predict the development of a niche after a first CS. However, several factors seem to influence scar healing which indicates possibilities for future prevention such as surgical experience and suture material. The search for additional risk factors that play a role in development of a niche should be continued to improve the discriminative ability.

Uterine niche is associated with adverse in vitro fertilization and intracytoplasmic sperm injection outcomes: a retrospective cohort study

OBJECTIVE

To investigate the relationship between uterine niche and reproductive outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

DESIGN

A retrospective cohort study.

SETTING

A reproductive medicine center.

PATIENT(S)

A total of 2,449 women with cesarean section history who underwent 2,874 IVF/ICSI cycles between January 2015 and December 2019.

INTERVENTION(S)

A defect deeper than 2 mm visible under three-dimensional transvaginal sonography or hysteroscopy was defined as uterine niche. The IVF/ICSI outcomes of the first embryo transfer were obtained by telephone interview 1 year after embryo transfer regardless of fresh embryos or frozen-thawed embryos. Generalized estimating equations, logistic regression analyses, and propensity score matching were applied to clarify the relationship between uterine niche and IVF/ICSI outcomes.

MAIN OUTCOME MEASURE(S)

Primary outcome was live birth rate. Secondary outcomes were positive human chorionic gonadotropin test results, clinical pregnancy rate, implantation rate, miscarriage rate, and ectopic pregnancy rate.

RESULTS

After excluding 48 cycles for uterine malformation; 18 cycles for chromosome abnormality; 281 cycles for no available embryo or no embryo transfer; 5 cycles for oocyte donation; and 7 cycles for loss of follow-up, we finally included 2,231 women with 2,515 cycles in our study. Compared with women without niche, women with niche had reduced live birth rate (18.99% vs. 31.51%, : 0.51, 95% CI: 0.34-0.77), positive human chorionic gonadotropin test rate (34.08% vs. 46.40%, adjusted odds ratio [aOR]: 0.61, 95% confidence interval [CI]: 0.43-0.87), clinical pregnancy rate (29.05% vs. 42.25%, aOR: 0.57, 95% CI: 0.39-0.82) and implantation rate (25.87% vs. 36.95%, aOR: 0.53, 95% CI: 0.38-0.76). In all the sensitivity analyses, the niche group had a 7.28% to 18.22% increase in miscarriage rate even not all of them were statistically significant.

CONCLUSION(S)

Uterine niche may have a detrimental effect on subsequent fertility of women with cesarean section history undergoing IVF/ICSI treatment. Practitioners should be noted that women with uterine niches may be associated with adverse IVF/ICSI outcomes.

Frequency and associated symptoms of isthmoceles in women 6 months after caesarean section: a prospective cohort study

PURPOSE

The purpose of this study was to determine the frequency of detection of isthmoceles by ultrasound 6 months after caesarean section (CS) and which symptoms associated with isthmocele formation occur after CS. Subsequently, it was determined how often the ultrasound finding "isthmocele" coincided with the presence of complaints.

METHODS

A prospective multicentre cohort study was conducted with 546 patients from four obstetric centres in Berlin, who gave birth by primary or secondary CS from October 2019 to June 2020. 461 participants were questioned on symptoms 3 months after CS; 329 participants were included in the final follow-up 6 months after CS. The presence of isthmoceles was determined by transvaginal sonography (TVS) 6 months after CS, while symptoms were identified by questionnaire.

RESULTS

Of the 329 women, 146 (44.4%) displayed an isthmocele in the TVS. There was no statistically significant difference in the manifestation of symptoms between the two groups of women with and without isthmocele; however, when expressed on a scale from 1 to 10 the intensity of both scar pain and lower abdominal pain was significantly higher in the set of women that had shown to have developed an isthmocele (p = 0.014 and p = 0.031, respectively).

CONCLUSION

The prevalence of isthmoceles 6 months after CS was 44.4%. Additionally, scar pain and lower abdominal pain were more pronounced when an isthmocele was also observed in the TVS.

TRIAL REGISTRATION

Trial registration number DRKS00024977. Date of registration 17.06.2021, retrospectively registered.

Increased amplitude of subendometrial contractions identified by ultrasound speckle tracking in women with a caesarean scar defect

RESEARCH QUESTION

What is the effect of a caesarean scar defect on subendometrial contractions?

DESIGN

Prospective cohort study in a Dutch medical centre including women with a niche in the uterine caesarean section scar. Data were compared with controls without a caesarean section scar. All women underwent a 5-min recording by transvaginal ultrasound at four phases in the menstrual cycle: during menses; late follicular; early luteal; or late luteal phase. Uterine motion analysis was evaluated by dedicated speckle tracking using two-dimensional optical flow.

MAIN OUTCOME

amplitude of the subendometrial contractions.

RESULTS

Thirty-one women with a niche in the uterine scar and 11 controls, matched for menstrual cycle phase, were included. The amplitude of the subendometrial contractions was significantly higher in women with a niche compared with controls during all phases of the menstrual cycle (menses P < 0.001; late follicular P < 0.001; early luteal P = 0.028; late luteal P = 0.003). Velocity was lower in women with a niche during late follicular phase only (P = 0.012). A positive correlation between niche sizes (depth, length) and amplitude of subendometrial contractions was found.

CONCLUSION

Subendometrial contractions were affected in women with a niche in the caesarean section scar compared with women who had not undergone a previous caesarean section. Contraction amplitude was higher and independent of the menstrual phase. These findings may cause postmenstrual spotting, dysmenorrhoea and lower implantation rates in women with a niche. Future studies should investigate this association and the underlying pathways.

Comparative effectiveness of transvaginal repair vs. hysteroscopic resection in patients with symptomatic uterine niche

Objective

To compare the efficacy of transvaginal repair and hysteroscopic resection in improving niche associated postmenstrual spotting.

Methods

The improvement rate of postmenstrual spotting in women who underwent transvaginal repair or hysteroscopic resection treatment was assessed retrospectively in patients accepted at the Niche Sub-Specialty Clinic in International Peace Maternity and Child Health Hospital between June 2017 and June 2019. Postoperative spotting symptom within one year after surgery, pre- and postoperative anatomical indicators, women' satisfaction with menstruation and other perioperative parameters were compared between the two groups.

Results

68 patients in the transvaginal group and 70 patients in the hysteroscopic group were included for analysis. The improvement rate of postmenstrual spotting in the transvaginal group at the 3rd, 6th, 9th, and 12th months after surgery was 87%, 88%, 84%, and 85%, significantly higher than 61%, 68%, 66%, and 68% in the hysteroscopic group, respectively (P < 0.05). The total days of spotting improved significantly at the 3rd month after surgery but did not change over time within one year in each group (P > 0.05). After surgery, the disappearance rates of the niche are 68% in transvaginal group and 38% in hysteroscopic group, however, hysteroscopic resection had shorter operative time and hospitalization duration, less complications, and lower hospitalization costs.

Conclusion

Both treatments can improve the spotting symptom and anatomical structures of uterine lower segments with niches. Transvaginal repair is better in thickening the residual myometrium than hysteroscopic resection, however, hysteroscopic resection has shorter operative time and hospitalization duration, less complications, and lower hospitalization costs.

Pregnancy in an isthmocele: A rare case from Nepal

An infrequent form of ectopic pregnancy, pregnancy in an isthmocele can be hazardous due to hemorrhage or uterine rupture. With no clear guidelines for the management of this condition, surgery is the preferred option.

New ultrasonographic risk assessment of uterine scar dehiscence in pregnancy after cesarean section

PURPOSE

We performed a new ultrasonographic risk assessment of uterine scar dehiscence, which is a potential risk factor for uterine rupture, in pregnancy after cesarean section. We attempted to shed light on the natural course of the change in the lower uterine segment by means of a longitudinal investigation through quantitative and qualitative evaluations.

METHODS

This retrospective single-center study involved 31 women with a normal singleton pregnancy delivered by elective cesarean section between 2020 and 2021, with all women showing a "niche" in the lower uterine segments. The lower uterine segments were assessed qualitatively and quantitatively using transvaginal ultrasonography at 16-21, 22-27, and 28-33 weeks of gestation, and subjects were divided into two groups: those with uterine dehiscence (12 women) and those without uterine dehiscence (19 women), depending on the gross findings of the lower uterine segments at cesarean section. Analyses were performed using Wilcoxon's rank-sum and Mann-Whitney U test with a significance level of P < 0.05.

RESULTS

The lower uterine segments changed from V-shaped to U-shaped to thin as gestation progressed and was more prominent in the uterine dehiscence group, occurring mostly at 22-27 weeks. At 22-27 weeks, the median myometrial thickness in the uterine dehiscence group was lower than in the group without uterine dehiscence (P = 0.0030). Thinning of the lower uterine segments had moved the cephalad at 22-27 and 28-33 weeks in cases with and without uterine dehiscence.

CONCLUSION

A model of morphological changes in the niche was constructed based on qualitative and quantitative assessments. The morphological changes and actual thinning of the lower uterine segments were prominent in the second trimester in women considered to have uterine scar dehiscence.

Prevalence, definition, and etiology of cesarean scar defect and treatment of cesarean scar disorder: A narrative review

Background

Cesarean scar defects (CSD) are caused by cesarean sections and cause various symptoms. Although there has been no previous consensus on the name of this condition for a long time, it has been named cesarean scar disorder (CSDi).

Methods

This review summarizes the definition, prevalence, and etiology of CSD, as well as the pathophysiology and treatment of CSDi. We focused on surgical therapy and examined the effects and procedures of laparoscopy, hysteroscopy, and transvaginal surgery.

Main findings

The definition of CSD was proposed as an anechoic lesion with a depth of at least 2 mm because of the varied prevalence, owing to the lack of consensus. CSD incidence depends on the number of times, procedure, and situation of cesarean sections. Histopathological findings in CSD are fibrosis and adenomyosis, and chronic inflammation in the uterine and pelvic cavities decreases fertility in women with CSDi. Although the surgical procedures are not standardized, laparoscopic, hysteroscopic, and transvaginal surgeries are effective.

Conclusion

The cause and pathology of CSDi are becoming clear. However, there is variability in the prevalence and treatment strategies. Therefore, it is necessary to conduct further studies using the same definitions.

Correlation between Blood Glucose Levels on Niche Incidence after Cesarean Section

BACKGROUND: Long-term sequelae of cesarean section (CS) is formation of niche in CS surgical scar. Blood glucose involved in wound healing process after CS. AIM: This study was to find correlation of blood glucose level with niche in CS patients. METHODS: This research was an observational and analytic study with case series design conducted at Department of Obstetrics and Gynecology, Universitas Sumatera Utara, RSUP H Adam Malik Medan, and Sundari Hospital Medan Starting from July to August 2022. To assess correlation between variables, eta test was used to assess the correlation of blood glucose with incidence of niche. The analysis results were said to be significant if p < 0.05, with 95% CI. RESULTS: Mean of patients were in 21–29 years (70%), multiparity with 12 patients (40%), aterm gestational age with 30 patients (100%), 16 patients (53.3%) with anteflexion uterus, previous CS 2 times were the majority with 9 patients (30%), and 17 patients (56.7%) were elective CS. Incidence of niche was 63.3%. Triangular were the most found niche with 11 patients (36.7%). Mean of total myometrial thickness, depth of niche, and residual myometrial thickness were 5.23 ± 11.2 mm, 2.44 ± 2.75 mm, and 5.23 ± 11.22 mm, respectively. Mean blood sugar level was 103.3 ± 17.4 mg/dl. From eta analysis, there was no correlation between blood glucose levels post-CS patients using eta test with p = 0.872. CONCLUSION: There was no significant correlation between blood glucose levels on niche incidence in post-CS patients.

Change of the residual myometrial thickness during pregnancy in women who underwent laparoscopic niche resection compared with controls without niche surgery: a prospective comparative cohort study

BACKGROUND

Reduced residual myometrial thickness before and during pregnancy is associated with uterine rupture or dehiscence after vaginal birth after cesarean delivery. Laparoscopic niche resection performed in case of gynecologic symptoms has shown to increase residual myometrial thickness 6 months after surgery.

OBJECTIVE

This study aimed to evaluate the change in residual myometrial thickness from baseline value before pregnancy to the third trimester of pregnancy in women with and without laparoscopic niche resection and evaluate niche presence, niche size during pregnancy vs before pregnancy, and obstetrical outcomes, including uterine rupture and dehiscence in both study groups.

STUDY DESIGN

This was a prospective cohort study conducted in an academic medical center. Of note, 2 groups of pregnant women with a previously diagnosed niche were included: (1) women with a large symptomatic niche (residual myometrial thickness of <3 mm) followed by laparoscopic niche resection (LNR group) and (2) women with a niche without niche resection because of minimal symptoms or a residual myometrial thickness of ≥3 mm diagnosed before current pregnancy (expectant group). Participants underwent a transvaginal ultrasound at 12, 20, and 30 weeks of gestation. Changes in residual myometrial thickness and changes in niche measurements over time were analyzed with linear mixed models.

RESULTS

A total of 100 women were included, 61 in the LNR group and 39 in the expectant group. The change in residual myometrial thickness from baseline value before niche resection to the third trimester of pregnancy was +2.0 mm in the LNR group vs -1.6 mm in the expectant group (P<.001). Residual myometrial thickness decreased from the first trimester of pregnancy onward in both groups. Although residual myometrial thickness was thinner at baseline in the LNR group, it was thicker in the LNR group than in the expectant group during all trimesters: 3.2 mm (P<.001) in the first trimester of pregnancy, 2.5 mm (P<.001) in the second trimester of pregnancy, and 1.8 mm (P=.001) in the third trimester of pregnancy. Uterine dehiscence was reported in 1 of 50 women (2%) in the LNR group and 7 of 36 women (19%) in the expectant group (P=.007) and was related to the depth of niche-to-residual myometrial thickness ratio before pregnancy (after niche resection) and residual myometrial thickness in the second trimester of pregnancy. No uterine rupture was reported. Most patients received a scheduled cesarean delivery in both groups. There was more blood loss during subsequent cesarean delivery in the LNR group than in the expectant group.

CONCLUSION

Here, laparoscopic niche resection resulted in an increased residual myometrial thickness during a subsequent pregnancy. Moreover, a lower number of dehiscence was found in the LNR group than in the expectant group without niche surgery. Per-section blood loss was higher in the LNR group than in the expectant group. In general, laparoscopic niche resection is performed to improve gynecologic symptoms. Currently, there is no evidence to support a laparoscopic niche resection to improve obstetrical outcomes, but the trend toward more uterine dehiscence encourages further research.

Prediction of the relationship of cesarean section scar niche and postmenstrual spotting: is there any relation?

Background

Postmenstrual spotting has recently been related to a discontinuation of the myometrium at the site of a previous cesarean section called "CS scar niche". There was no consensus regarding the gold standard method for the assessment of the niche. Recently, Magnetic resonance imaging (MRI) has shown promise in the evaluation of the niche. Our study aims to assess the role of MRI in the evaluation of the CS scar niche characters and its association with post-menstrual spotting.

Results

A total of 65 patients with CS niche were prospectively included in this study and subdivided into two groups, according to presence or absence of postmenstrual spotting (Group A; 34 patients with postmenstrual spotting and Group B; 31 patients without spotting). All patients were examined using a 1.5 T MRI unit. CS scar niche volume was significantly higher among women with post-menstrual spotting (0.57 ± 0.07 vs. 0.07 ± 0.05 (cm3); P < 0.001). Also, women with post-menstrual spotting have significantly higher scar length (9.38 ± 3.06 vs. 5.02 ± 2.10 (mm); P < 0.001), scar depth (6.95 ± 3.16 vs. 3.23 ± 0.99 (mm); P < 0.001), scar width (15.78 ± 3.94 vs. 9.87 ± 1.84 (mm); P < 0.001) in comparison to those without post-menstrual spotting.

Scar depth (> 7.4 mm) had 81% sensitivity and 97% specificity for prediction of post-menstrual spotting with overall accuracy was 88.7%. While scar width (> 12.8 mm) had 71% sensitivity and 97% specificity for prediction of post-menstrual spotting with overall accuracy was 83.3%. Scar volume (> 0.15 cm3) had 97% sensitivity and 100% specificity for prediction of post-menstrual spotting with overall accuracy was 98.4%.

Conclusion

MRI measures (CS scar volume, depth, and width) are predictors for postmenstrual spotting in patients with CS scar niche, and scar volume is the most powerful predictor.

Cesarean scar defects and abnormal uterine bleeding: a systematic review and meta-analysis

OBJECTIVE

To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we aimed to evaluate the risk and pattern(s) of CSD-associated AUB in addition to exploring the relationship between defect morphology with bleeding symptoms.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Patients with CSD and reports of uterine bleeding as an outcome were identified in 60 studies from database searches.

INTERVENTIONS

Studies that investigated CSD (as defined by investigators) and reported uterine bleeding, menstrual bleeding, or AUB as an outcome were included.

MAIN OUTCOME MEASURES

The prevalence and risk of AUB (intermenstrual, postmenstrual, and unscheduled bleeding) in patients with confirmed CSD.

RESULTS

Nine studies reported on the prevalence of AUB in patients with a confirmed CSD. Patients with CSD were more likely to experience AUB, compared with those without CSD (relative risk, 3.47; 95% confidence interval [CI], 2.02-5.97; 6 studies, 1,385 patients; I² = 67%). In a population of patients with at least 1 cesarean delivery, the prevalence of AUB in those with CSD was 25.5% (95% CI, 14.7-40.5; 6 studies, 667 patients, I² = 93%). However, symptom prevalence was much higher in patients presenting for imaging for a gynecologic indication where the prevalence of AUB in the presence of a CSD was 76.4% (95% CI, 67.8-83.3; 5 studies, 505 patients; I² = 71%). The mean menstrual duration in symptomatic patients with CSD was 13.4 days (95% CI, 12.6-14.2; 19 studies, 2,095 patients; I² = 96%), and the mean duration of early-cycle intermenstrual bleeding was 6.8 days (95% CI, 5.7-7.8 days; 9 studies, 759 patients; I² = 93%). The most common descriptor of CSD-associated AUB was "brown discharge". Patients with larger CSD experienced more bleeding symptoms.

CONCLUSION

There is a strong and consistent association between patients with CSD and AUB. These patients experience a unique bleeding pattern, namely prolonged menstruation and early-cycle intermenstrual bleeding. These data should provide impetus for including CSD as a distinct entity in AUB classification systems. High heterogeneity in our results calls for standardization of nomenclature and outcome reporting for this condition.

Uterine disorders and iron deficiency anemia

Abnormal uterine bleeding (AUB) is a clinical entity which can lead to iron deficiency anemia. Classification according to the acronym PALM-COEIN (polyp, adenomyosis, leiomyoma, malignancy, and hyperplasia; coagulopathy, ovulatory dysfunction, endometrial, iatrogenic, and not otherwise classified) provides a structured approach to establish the cause of AUB. The goal of this review is to discuss the different mechanisms and the relationship between uterine disorders and AUB. Heavy menstrual bleeding, a subgroup of AUB, is more closely related to the presence of uterine fibroids. The relationship between heavy menstrual bleeding and uterine fibroids remains poorly characterized, particularly the understanding of endometrial function in women with structural myometrial features such as leiomyomas. A number of theories have been proposed in the literature and are discussed in this review. Uterine adenomyosis is also a frequent cause of AUB, and its pathogenesis is still far from being fully elucidated. The mechanisms contributing to its development are multifactorial. Many theories lean toward invasion of the myometrium by endometrial cells. Both clinical and basic studies favor the theory of direct invasion, although de novo development of adenomyosis from Müllerian rests or stem cells has not been ruled out. Development of adenomyotic lesions involves repeated tissue injury and repair. In addition, this review describes the other causes of AUB such as endometrial polyps, cesarean scar defects, and uterine vascular abnormalities. Endometrial polyps are often asymptomatic, but approximately 68% of women have concomitant AUB. Histologic alterations in the lower uterine segment in patients who had undergone cesarean sections were identified and may explain the cause of AUB.

Complications of Caesarean delivery part 2: Non-pregnant and pregnancy-related complications

INTRODUCTION

With the rise in Caesarean deliveries, complications related to the procedure are increasingly encountered. Sonography has an indispensable role in the assessment of these complications and is often the first-line investigation of choice.Topic description: Part 2 of this pictorial review summarises the non-pregnant and pregnancy-related complications of Caesarean deliveries.

DISCUSSION

Non-pregnant complications include Caesarean scar defects, scar endometriosis and malpositioned intrauterine devices. Complications related to future gestations include scar ectopic pregnancy, abnormal placentation and intrapartum uterine dehiscence or rupture. Key sonographic features of these conditions are illustrated. Pitfalls, mimics, limitations and indications for cross-sectional imaging are discussed.

CONCLUSION

Sound knowledge of the sonographic features of common non-pregnant and pregnancy-related complications of Caesarean delivery will facilitate accurate diagnosis, timely management and improved patient outcomes.

The Impact of Uterine Incision Closure Techniques on Post-cesarean Delivery Niche Formation and Size: Sonohysterographic Examination of Nonpregnant Women

OBJECTIVE

To compare the prevalence and size of residual niche in the nongravid uterus following Cesarean delivery (CD) with different hysterotomy closure techniques (HCTs).

METHODS

Saline infusion sonohysterogram (SIS) was performed in women after one prior CD, documenting the presence or absence of a postoperative niche and measuring its depth, width, length, and residual myometrial thickness. Women were grouped by HCT: Technique A (endometrium-free) and Technique B (routine non-endometrium-free). The primary outcome was the prevalence of a clinically significant niche, defined as a depth of >2 mm. HCT groups were compared using χ² , T-test (ANOVA), and analyzed using logistic regression and two-sided test (P < .05).

RESULTS

Forty-five women had SIS performed, 25 and 20 via Technique A and B, respectively. Technique groups varied by average interval time from CD to SIS (13.6 versus 74.5 months, P = 0.006) but were otherwise similar. Twenty niches were diagnosed, 85% of which were clinically significant, including five following Technique A, nine following Technique B with double-layer closure, and three following Technique B with single-layer (P = .018). The average niche depth was 2.4 mm and 4.9 mm among the two-layer subgroups following Techniques A and B, respectively (P = .005). A clinically significant niche development was six times higher with Technique B when compared to Technique A (OR 6.0, 95% CI 1.6-22.6, P = .008); this significance persisted after controlling for SIS interval on multivariate analysis (OR 4.4, 95% CI 1.1-18.3, P = .04). The average niche depth was 5.7 ± 2.9 mm following Technique B with single-layer.

CONCLUSION

Hysterotomy closure techniques determine the prevalence of post-Cesarean delivery niche formation and size. Exclusion of the endometrium at uterine closure reduces the development of significant scar defects.

Levonorgestrel-Releasing Intrauterine Device Use Can Be a Treatment Option in Symptomatic Patients with Isthmocele

Levonorgestrel-releasing intrauterine devices have been used for contraception and treatment of heavy menstrual bleeding. There is only limited data about the effect of this on isthmocele. Here, we aimed to evaluate the effect of levonorgestrel-releasing intrauterine devices in a larger study population with a longer follow-up as compared to the literature on symptomatic patients with isthmocele. A total of 29 patients with symptomatic isthmocele and inserted levonorgestrel-releasing device were included in this prospective study. All patients were included at January 2020 and followed for 18 months. Sociodemographic findings, laboratory parameters, premenstrual spotting, postmenstrual spotting, menorrhagia, dysmenorrhea, and pelvic pain related to isthmocele were recorded. In sonography, width, length, area of isthmocele, and residual myometrial thickness were determined. The frequency of symptoms during follow-up was compared between visits and also compared between groups according to residual myometrial thickness. Premenstrual spotting and pelvic pain were significantly reduced at 6th months (48.3 to 10.3%, p = 0.007 and 34.5 to 10.3%, p = 0.039, respectively) and no significant change was detected until the end of follow-up period. Postmenstrual spotting reduced at 6th months (96.6 to 34.5%, p < 0.001) and also significant change was detected between 6 and 12th months (34.5% vs 13.8%, p = 0.031). Menorrhagia and dysmenorrhea disappeared at 12th months. No association was found between residual myometrial thickness and the frequency of symptoms for each follow-up. Levonorgestrel-releasing intrauterine devices are useful and reliable therapeutic tools for symptomatic isthmocele patients who do not desire fertility, regardless of residual myometrial thickness.

Isthmocele—a neglected cause of secondary infertility and implantation failure: A case report

Isthmocele is myometrial scar tissue that develops after cesarean section delivery. In this case, other more prevalent pathologies delayed isthmocele diagnosis as the main cause of the patient's symptoms. Considering isthmocele is a fluid‐filled pouch‐like defect associated with infection caused by stagnant menstrual blood, its immunological aspects lead to implantation failure.

Definition of large niche after Cesarean section based on prediction of postmenstrual spotting: Chinese cohort study in non-pregnant women

OBJECTIVE

A large niche after Cesarean section (CS) is associated with long-term complications, of which postmenstrual spotting is associated positively with the size of the niche. However, the diagnosis of a large niche in the literature is inconsistent and the definition is largely subjective. The aim of this study was to generate a definition for a large niche in non-pregnant women based on the presence of postmenstrual spotting.

METHODS

Women who had undergone CS in our hospital between January 2012 and June 2017 were selected randomly from our database, contacted by telephone and subsequently examined between January 2016 and June 2020. Eligible for inclusion were non-pregnant women who had their last CS more than 1 year earlier and agreed to undergo transvaginal sonography (TVS). All participants underwent examination of their CS scar by TVS (two-dimensional color Doppler) during the midfollicular phase. Niche depth, length, width, residual myometrial thickness (RMT), adjacent myometrial thickness (AMT) and ratio of niche depth/AMT were recorded. Women diagnosed with a niche, defined as an indentation at the site of the CS with a depth of at least 2 mm, were classified into two groups (symptomatic or asymptomatic) according to whether they experienced postmenstrual spotting. Logistic regression analysis was used to establish the best cut-off values for the niche parameters to predict postmenstrual spotting. A new definition was generated based on the niche parameters with the highest area under the receiver-operating-characteristics (ROC) curve (AUC) for the prediction of postmenstrual spotting.

RESULTS

A total of 727 women who had a CS > 1 year earlier underwent TVS examination, of whom 263 were diagnosed with a niche (prevalence of 36.2%). Of these, 160 women experienced postmenstrual spotting and 103 were asymptomatic. The three variables with the highest AUC for prediction of postmenstrual spotting were niche depth/AMT ratio (AUC, 0.798; 95% CI, 0.745-0.852), niche depth (AUC, 0.731; 95% CI, 0.668-0.795) and RMT (AUC, 0.683; 95% CI, 0.618-0.748). Based on the best cut-offs according to ROC-curve analysis, a large niche was defined as: niche depth ≥ 0.50 cm, RMT ≤ 0.21 cm or niche depth/AMT ratio ≥ 0.56. The prevalence of a large niche according to this definition was 22.4% (163/727). The new definition had a specificity of 61.17% (95% CI, 52.34-70.41%) and sensitivity of 76.87% (95% CI, 70.28-84.16%) for a large niche.

CONCLUSION

This study has provided a new definition for a large niche after CS. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prospective Evaluation of the Ultrasound Signs Proposed for the Description of Uterine Niche in Nonpregnant Women

OBJECTIVES

To evaluate the new ultrasound-based signs for the diagnosis of post-cesarean section uterine niche in nonpregnant women.

METHODS

We investigated prospectively a cohort of 160 consecutive women with one previous term cesarean delivery (CD) between December 2019 and 2020. All women were separated into two subgroups according to different stages of labor at the time of their CD: subgroup A (n = 109; 68.1%) for elective CD and CD performed in latent labor at a cervical dilatation (≤4 cm) and subgroup B (n = 51; 31.9%); for CD performed during the active stage of labor (>4 cm).

RESULTS

Overall, the incidence of a uterine niche was significantly (P < .001) higher in women who had an elective (20/45; 44.4%) compared with those who had an emergent (21/115; 18.3%) CD. Compared with subgroup B, subgroup A presented with a significantly (P = .012) higher incidence of uterine niche located above the vesicovaginal fold and with a significantly (P = .0002) lower proportion of cesarean scar positioned below the vesicovaginal fold. There was a significantly (P < .001) higher proportion of women with a residual myometrial thickness (RMT) > 3 mm in subgroup A than in subgroup B and a significant negative relationship was found between the RMT and the cervical dilatation at CD (r = -0.22; P = .008).

CONCLUSIONS

Sonographic cesarean section scar assessment indicates that the type of CD and the stage of labor at which the hysterotomy is performed have an impact on the location of the scar and the scarification process including the niche formation and RMT.

Fantastic niches and where to find them: the current diagnosis and management of uterine niche

Background

Caesarean section (CS) scar niche is a well recognised complication of caesarean delivery and is defined as an indentation at the site of the CS scar with a depth of at least 2mm.

Objectives

To review systematically the medical literature regarding the current diagnosis and management of uterine niche

Materials and methods

We carried out a systematic review using MeSH terms ‘niche’ OR ‘sacculation’ OR ‘caesarean scar defect’ OR ‘caesarean section scar’ OR ‘uterine defect’ OR ‘isthmocele.’ Articles included were peer-reviewed and in English language.

Main outcome measures

Prevalence, symptoms, diagnosis, pathophysiology and management of uterine niche.

Results

CS scar niche is common and, in a subgroup, produces a range of symptoms including post-menstrual bleeding, dyspareunia and subfertility. It may be linked to use of locked sutures during CS closure. Niche repair can be achieved laparoscopically or hysteroscopically and appears to improve symptoms, although solid conclusions regarding fertility outcomes cannot be drawn.

Conclusions

CS scar niche is associated with a range of symptoms. Repair may aid subfertile patients and those with post-menstrual spotting. The presence of a niche is probably irrelevant in the absence of symptoms.

What is new?

LNG-IUS and surgical repair appear to improve symptoms in those with a niche.