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 (ß = 0.257, 95% confidence interval [CI] 0.040-0.473, P = 0.020) and radiomically assessed minor axis length (ß = 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 (ß = -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.

Outcomes of Cesarean Scar Pregnancies in Early Gestation According to the New Delphi Consensus Criteria.

OBJECTIVES: Clinical evaluation of the new Delphi consensus definition of cesarean scar pregnancy (CSP) in early gestation. METHODS: A retrospective cohort of 36 women diagnosed with CSP and treated with combined local and systemic methotrexate (MTX) between 2008 and 2021. The CSPs were classified according to the new Delphi consensus criteria into three subgroups based on the depth of the gestational sac herniation in the sagittal plane. Subgroup A included 8 (22.2%) cases in which the largest part of the gestational sac protruded toward the uterine cavity. Subgroup B included 22 (61.1%) cases in which the largest part of the gestational sac was embedded in the myometrium, and subgroup C included 6 (16.7%) cases in which the gestational was partially located outside the outer contour of the cervix or uterus. RESULTS: The ß-HCG level upon admission was significantly lower in subgroup A than in subgroups B or C (11,075 ± 7109, 18,787 ± 16,585, and 58,273 ± 55,267 mIU/mL, respectively, P = .01). All subgroup C patients had repeated courses of MTX and surgical interventions (laparotomy, uterine artery embolization, and operative hysteroscopy) at double the rate of subgroups A or B (100, 50, and 40.9%, respectively, P = .036). The duration of hospitalization was significantly shorter in subgroup A than in subgroups B or C (1.9 ± 1.5, 2.1 ± 1.1, and 5.4 ± 4.9 days, P = .01). CONCLUSIONS: The outcome according to Delphi consensus criteria for defining CSP in early gestation has implications for clinical decision-making, patient care, and the follow-up of CSP.

Bacterial colonization at caesarean section defects in women of secondary infertility: an observational study.

BACKGROUND: Delayed childbearing has been noted in a high percentage of women with a previous Caesarean section (CS). Many women with CS scar defects (CSDs) present with clinical symptoms of irregular vaginal bleeding. The present study aimed to investigate bacterial colonies at CSDs in women suffering from secondary infertility. METHODS: This observational study included 363 women with secondary infertility who visited the Assisted Reproduction Unit between 2008 and 2013. Among them, 172 women with a previous CS and 191 women with no previous CS were approached. The women with a previous CS had their CS operations in the past 1 to 14 years, with a mean of 3.5 years. The presence of CSDs was detected by vaginal ultrasonography. Bacteriology cultures of specimens taken from the uterine niches in those with CSDs were collected during Day 7 to Day 10 of the follicular phase. Specimens were obtained from the endocervical canal for bacterial culture in those without CSDs. The main outcome measure was the detection of the growth of bacterial colonies. RESULTS: CSDs were found in 60.4% (96 of 159) of women with a previous CS. In women with a previous CS, bacterial colonies were identified in 89.6% (86 of 96) and 69.8% (44 of 63) of women with and without CSDs, respectively. In women with no previous CS, 49.7% (88 out of 177) of bacterial cultures of endocervical samples showed bacterial colony growth. Gram-positive cocci (P = 0.0017, odds ratio (OR) = 1.576, 95% confidence intervals (CI) -22.5 to - 5.4) and Gram-negative rods (P = 0.0016, OR = 1.74, CI - 20.8 to - 5.0) were the most commonly isolated bacteria and contributed to approximately 90% of all microorganisms found in those with a previous CS. In women with a previous CS, more Gram-negative rods were isolated (P = 0.01, OR = 1.765, CI - 27.2 to - 3.8), especially Pseudomonas species (P = 0.02, OR = 1.97, CI - 16.7 to - 1.0), in those with visible CSDs than in those without CSDs. CONCLUSIONS: Bacterial colonization at CSDs was found in a high percentage of women with secondary infertility.

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.

The association between prior cesarean delivery and subsequent in vitro fertilization outcomes in women undergoing autologous, frozen-thawed single euploid embryo transfer.

BACKGROUND: The rates of cesarean deliveries continue to increase worldwide. Previous work suggests an association between a previous cesarean delivery and reduced fertility in natural conception and in vitro fertilization treatment cycles. To our knowledge, there is no published research that explored the relationship between a previous cesarean delivery and the clinical outcomes after in vitro fertilization and the subsequent transfer of a single frozen-thawed euploid embryo. OBJECTIVE: This study aimed to investigate the relationship between the previous mode of delivery and subsequent pregnancy outcomes in patients undergoing a single frozen-thawed euploid embryo transfer after in vitro fertilization. STUDY DESIGN: A retrospective cohort study was performed at a single academic fertility center from January 2012 to April 2020. All women with a history of a live birth undergoing autologous, frozen-thawed single euploid embryo transfers were identified. Cases included patients with a single previous cesarean delivery; controls included patients with a single previous vaginal delivery. Only the first embryo transfer cycle was included. The primary outcome was the implantation rate. Secondary outcomes included ongoing pregnancy and live birth rates, biochemical pregnancy rate, and clinical miscarriage rate. RESULTS: A total of 525 patients met the inclusion criteria and were included in the analysis. Patients with a previous cesarean delivery had a higher body mass index (24.5±4.5 vs 23.4±4.1; P=.004) than those in the vaginal delivery cohort; the rest of the demographic data were otherwise similar. In a univariate analysis, the implantation rate was significantly lower in patients with a previous cesarean delivery (111/200 [55.5%] vs 221/325 [68.0%]; P=.004). After adjusting for the relevant covariates, a previous cesarean delivery was associated with a 48% reduction in the odds of implantation (adjusted odds ratio, 0.52; 95% confidence interval, 0.34-0.78; P=.002). In addition, after adjusting for the same covariates, a previous cesarean delivery was significantly associated with a 39% reduction in the odds of an ongoing pregnancy and live birth (adjusted odds ratio, 0.61; 95% confidence interval, 0.41-0.90; P=.01). There were no differences in the biochemical pregnancy rates or clinical miscarriage rates. CONCLUSION: This study demonstrated a marked reduction in implantation and ongoing pregnancy and live birth associated with a previous cesarean delivery in patients undergoing a single euploid embryo transfer. Our work stresses the importance of reducing the primary cesarean delivery rates at a national level and elucidating the mechanisms behind the substantially lower implantation rates after a cesarean delivery.

Position and integrity of uterine scar are determined by degree of cervical dilatation at time of Cesarean section.

OBJECTIVE: Abnormal placental invasion is more common after an elective Cesarean delivery, suggesting that prelabor Cesarean section (CS) increases the likelihood of the CS scar being above the internal cervical os and predisposing to a scar pregnancy in the future. The aim of this study was to assess the location and integrity of the CS scar in postpartum women delivered by CS at different stages of labor. METHODS: This was a prospective cohort study of women at term who underwent a CS for the first time. In all women, cervical dilatation was determined by digital examination at the time of the CS. All patients had a transvaginal ultrasound examination to assess the location of the CS scar in relation to the internal cervical os, as well as the presence of a scar niche. RESULTS: A total of 407 pregnant women were recruited into the study: 103 with cervical dilatation ≤ 2 cm, 261 with cervical dilatation 3-7 cm and 43 with cervical dilatation ≥ 8 cm at the time of the CS. A statistically significant correlation was observed between cervical dilatation at the time of the CS and the position of the CS scar. The scar was positioned in the uterus above the internal cervical os in 97.1% (100/103) of women delivered at a cervical dilatation of 0-2 cm, whereas the scar was located at or below the internal cervical os in 97.7% (42/43) of cases delivered at a cervical dilatation of 8-10 cm (P < 0.001). A uterine-scar defect (niche) was observed in 38.1% (64/168) of women with the scar located above, compared with 18.0% (43/239) of those with the scar situated at or below, the internal cervical os (P < 0.001). CONCLUSIONS: Prelabor and early-labor Cesarean delivery are associated with an increased prevalence of a scar in the uterine cavity as well as a scar niche. CS in late labor is associated with the uterine scar being situated in the endocervical canal and with a lower incidence of a niche. The position and integrity of the CS scar after prelabor and early-labor Cesarean delivery explain the predisposition to abnormal placental invasion in subsequent pregnancy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Is Hysteroscopy a Good Option to Manage Severe Cesarean Scar Defect?

STUDY OBJECTIVE: To compare the outcomes of hysteroscopic management in women with a severe or nonsevere symptomatic cesarean scar defect (residual myometrium ≤3-mm vs >3-mm, respectively). DESIGN: Retrospective cohort study. SETTING: Gynecology department of a teaching hospital. PATIENTS: Seventy-one women with an operative hysteroscopy for a symptomatic defect (49 with severe defects and 22 with nonsevere ones). INTERVENTIONS: Operative hysteroscopy for cesarean scar defect in women with a severe defect (residual myometrium ≤3-mm) and with nonsevere defect (residual myometrium >3-mm). MEASUREMENTS: The main objective was to compare success rates between the 2 groups. The secondary objectives were the comparisons of (1) the number of women who required more than 1 procedure, (2) the rate of complications, (3) the number of subsequent pregnancies, and (4) the evolution of residual myometrium thickness between the groups. MAIN RESULTS: The success rates were not significantly different between the groups (73.5% in the severe group and 63.6% in the nonsevere group [p = .40]). The number of women requiring more than 1 procedure was also similar, as were the rate of complications and the mean increase of myometrium thickness. The rate of subsequent pregnancies in women who were infertile was significantly higher in women with a severe defect (p = .04). CONCLUSION: The hysteroscopic approach seems to be a good way to manage cesarean scar defects even when the residual myometrium is thin. A prospective study is, however, necessary to confirm these findings.

Evaluation of cesarean scar after single- and double-layer hysterotomy closure: a prospective cross-sectional study.

BACKGROUND: We aimed to determine if there is a difference in the size of the cesarean scar defect using saline infusion sonography (SIS) performed on the postoperative third month in patients who underwent single- or double-layered unlocked closure of their uterine incision during their first cesarean delivery. METHODS: This study was conducted as a prospective cross-sectional study between February 2015 and January 2016 in patients admitted to the labour ward of the Kanuni Sultan Suleyman Training and Research Hospital who subsequently underwent their first delivery by cesarean section. Patients with a previous history of cesarean delivery, preterm pregnancies less than 34 gestational weeks, patients lost to follow-up or those who had an IUD inserted after delivery were excluded from the study. Out of the 327 patients who underwent primary cesarean delivery, 280 were included into the study. Patients were divided into two groups according to the single- (n:126) or double-layered (n:156) closure of their uterine incision. The maternal age, height, weight, obstetric and gynecologic histories, medical histories, indications for their cesarean delivery, technique of uterine closure, birth weight of the baby, duration of the cesarean delivery, need for extra suturing and transfusion were recorded. A Saline infusion sonography (SIS) was performed 3 months postoperatively to determine the presence, depth and length of the cesarean scar. The residual myometrial thickness overlying the scar defect and the fundal myometrial thickness were recorded. RESULTS: No difference was detected between the groups with respect to patient characteristics, whether the operation was elective or emergent, the type of anesthesia used, need for extra suturing, incidence of bladder injuries or uterine atony, need for blood transfusions, duration of labour or cervical dilatation and effacement between the two groups. No statistically significant difference was detected between the two groups with respect to the length and depth of the scar defect. CONCLUSION: Single- or double-layered closure of the uterus does not seem to affect the size of the uterine scar defect detected on SIS 3 months following the first cesarean delivery.

Robotic-assisted laparoscopic removal of cesarean scar ectopic and hysterotomy revision.

A 38-year-old gravida 6 para 2042 woman presented in consultation regarding management of a uterine defect, or "niche," following resolution of a cesarean scar ectopic pregnancy. She had 3 prior losses, followed by in vitro fertilization that resulted in 2 healthy births, both delivered by cesarean. A third in vitro embryo transfer resulted in the cesarean scar ectopic. After consideration of treatment options, she underwent multiple-dose parenteral methotrexate with eventual termination of the ectopic. Magnetic resonance imaging demonstrated a uterine defect, suspected to contain residual pregnancy tissue. Questions considered in her consultation included whether the defect should be repaired and, if so, from a hysteroscopic or laparoscopic approach, as well as her risk of intrauterine scarring, when, or if, it would be safe to pursue another pregnancy, and her subsequent risk of uterine rupture. Literature review regarding cesarean niche was helpful, but did not seem to completely inform this particular clinical scenario. She elected to proceed with robotic-assisted laparoscopic repair. The vesicovaginal space was opened to expose the defect. Dilute vasopressin was injected circumferentially around the defect to help minimize the use of electrosurgery in opening the hysterotomy. Scar overlying the defect was resected and pregnancy tissue removed. The hysterotomy was closed with delayed-absorbable barbed suture, extrapolating technique from laparoscopic myomectomy. The first layer was imbricated with a second, similar to a 2-layer closure in cesarean delivery. Follow-up magnetic resonance imaging revealed resolution of the defect. After several failed attempts at repeat in vitro fertilization, spontaneous pregnancy was achieved 18 months postoperatively. The pregnancy was uncomplicated and she underwent scheduled cesarean delivery of a healthy neonate at 37 weeks' gestation. The lower uterine segment was thick and developed, with no evidence of a dehiscence.

Factors Associated to the Presence of Isthmocele Diagnosed by Pelvic Ultrasound, Magnetic Resonance Imaging or Diagnostic Hysteroscopy: A Cross-Sectional Study.

We aimed to analyze the prevalence of isthmocele and factors associated with its onset within a cohort of women with previous history of cesarean section. A cross-sectional study with 90 women assessed from 2020 to 2022. Isthmocele was a composite variable diagnosed by transvaginal ultrasound (TVUS), magnetic resonance imaging (MRI) and/or diagnostic hysteroscopy (DxHys) and were asked about clinical symptoms, sociodemographic and obstetrical history and quality of life by the WHO-QOL questionnaire. Univariate and multivariate analysis (odds ratio (OR) plus 95% confidence intervals-CI) were performed to seek factors associated with the presence of isthmocele (5% significance level).The prevalence of isthmocele after combining MRI, TVUS and DxHys was 63.3% (n = 57). Women with isthmocele presented a higher body mass index (BMI) measured during delivery (32.70 ± 6.07 vs. 28.28 ± 9.86 kg/m2;p < 0.05) than women without isthmocele. Other sociodemographic variables, obstetrical history and WHO-QOL subdomains did not differ between groups. Within women with isthmocele, the residual myometrial mantle had an average of 4.97 ± 1.57 cm. Uterine volume was higher in the isthmocele group (103.95 vs. 81.34 cm3; p = 0.08), but with no statistical difference. Multivariate analysis (logistic regression) has reported that the factors associated with isthmocele were: higher BMI during delivery (aOR = 1.26[1.07-1.49];p < 0.05); longer interpartum interval (aOR = 1.22[1.03-1.46];p = 0.02) and presence of more than two cesarean sections (aOR = 2.16[1.16-4.01];p = 0.02). We concluded that a high prevalence of isthmocele was found. Women with previous cesarean section, with higher BMI during delivery and longer interdelivery interval were risk factors for the presence of isthmocele.

Investigating the risk factors for isthmocele development after cesarean delivery.

BACKGROUND: Cesarean delivery rates are increasing globally, raising concerns about associated complications such as isthmocele. Isthmoceles are pouch-like defects in the anterior uterine wall at the site of a prior cesarean delivery scar. OBJECTIVE: This study aimed to determine isthmocele prevalence, associated symptoms, and risk factors among women with a history of cesarean delivery. STUDY DESIGN: This cross-sectional study evaluated 297 women with prior cesarean delivery using transvaginal ultrasound to screen for isthmocele. Data on demographics, pregnancy details, comorbidities, and indications for cesarean delivery were collected. Isthmocele was defined sonographically as any niche or defect at the hysterotomy site. Descriptive and comparative analyses identified factors associated with isthmocele. RESULTS: Isthmocele prevalence was 65.3% (n=194). Abnormal vaginal bleeding was reported in 21.1% of participants, pelvic pain by 4.1% of participants, and both by 4.1% of participants. Compared to women without isthmocele, those with isthmocele were older (35.9 vs 31.6 years), had higher body mass index (26.8 vs 25.5 kg/m2), gravidity (1.8 vs 1.3), and parity (1.7 vs 1.2). Repeat cesarean delivery was more common (30.4% vs 12.6%) and elective cesarean delivery less common (33.5% vs 67.9%) among those with isthmocele. CONCLUSION: Over half of the women with history of cesarean delivery had an isthmocele. Abnormal bleeding was common. Advanced maternal age, obesity, repeat procedures, and certain comorbidities appear to increase risk. Further research on prevention and treatment is warranted given the high prevalence.

The Novel Parallel Closure Technique Compared to Single-Layer Closure of the Uterus After Primary Cesarean Section Decreases the Incidence of Isthmocele Formation and Increases Residual Myometrial Thickness.

Background Isthmocele or a scar defect is a relatively common consequence of cesarean section resulting in menstrual disturbances and infertility and may compromise the myometrial integrity of the uterus in women contemplating subsequent vaginal birth. Several preventive measures have been suggested, including the modification of surgical techniques used for the closure of the uterine incision. The current study aimed to compare the incidence of isthmocele and assess residual myometrial thickness in women who underwent single versus parallel layered closure to approximate the endo-myometrial layer during cesarean section. Methodology This retrospective study evaluated data of women undergoing their first cesarean section under elective conditions (n = 497) where the uterine incision was closed using a single (n = 295) or a parallel layer (n = 202) technique. Patients were evaluated twice, at 3-6 months and 18 months postpartum, with a transvaginal ultrasound noting the presence or absence of an isthmocele and measurement of the residual myometrial thickness. Results Regardless of the closure technique, 64 (12.9%) women had an ultrasound-diagnosed isthmocele. Significantly fewer patients in the parallel-layer closure group presented with an isthmocele both at 3-6 (13.6 vs. 6.9%; p = 0.019) and 18 months (16.3 vs. 7.8%; p = 0.009) postpartum. Residual myometrium was significantly thicker in the parallel-layer closure group (8.0 vs. 13.2 mm at 3-6 months postpartum; p = 0.000 and 7.2 vs. 12.3 mm at 18 months postpartum; p = 0.004). For all patients, a retroverted position of the uterus at 3-6 months follow-up examination significantly increased the frequency of isthmocele (36/395 (9.1%) with an anteverted uterus and 18/102 (17.6%) with a retroverted uterus; p = 0.002). In patients with a single-layer closure, a retroverted uterus at the 3-6-month follow-up was associated with an isthmocele in 29.5% (18/61) of patients, while no isthmocele was recorded when the uterus was retroverted in the parallel-layer closure group (0/41) (p = 0.001). At 18 months postpartum, of the 64 patients with an isthmocele, 26 (40.6%) presented with abnormal uterine bleeding mainly in the form of postmenstrual spotting. Of the 26 patients with abnormal bleeding, 23 were in the single-layer and three were in the parallel-layer closure group. Conclusions The parallel-layer closure when compared to a single-layer closure of the uterine incision in patients undergoing primary cesarean section decreased the incidence of isthmocele formation and increased residual myometrial thickness. More patients in the single-layer closure group had menstrual cycle disturbances at 18 months postpartum.

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.

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).

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.

Cesarean scar niche, fertility and uterine rupture during labor - A retrospective study.

OBJECTIVES: To determine how does a uterine niche diagnosed prior to conception, affects future fertility and obstetrical outcomes, in a group of patients with secondary infertility undergoing fertility treatments. STUDY DESIGN: A retrospective case-control study was performed, recruiting patients after cesarean delivery, before fertility treatment. Using stored ultrasound photos and video loops, we determined niche's sonographic parameters during the preconception period and retrieved the fertility and obstetrical outcomes thereafter. RESULTS: 104 patients met the inclusion criteria, and 86 were available for analysis. 56 (65%) had uterine niches larger than 2 mm in depth, and 30 (34%) had a uterine scar of 2 mm or less. Demographic characteristics were not different between groups. No statistically significant differences were observed regarding rates of implantation and clinical pregnancy between the groups. There were four cases of cesarean scar rupture during failed trial of labor (TOLAC), all of which were in the group with larger than 2 mm niche (33% of all TOLAC cases in the respected group). CONCLUSIONS: While it appears that pre-conception presence of uterine niches larger than 2 mm in depth does not adversely affect future fertility, these niches might serve as a risk factor for future uterine rupture during TOLAC.

Comparison of the efficacy of oral contraceptives and levonorgestrel intrauterine system in intermenstrual bleeding caused by uterine niche.

This study aimed to compare the effectiveness of oral contraceptives and a levonorgestrel intrauterine system in treating intermenstrual bleeding due to uterine niche. We retrospectively analyzed 72 patients with intermenstrual bleeding due to uterine niche from January 2017 to December 2021, of whom 41 were treated with oral contraceptives and 31 with a levonorgestrel intrauterine system. Post-treatment follow-ups at 1, 3, and 6 months were conducted to compare the efficiency and adverse effects between the two groups. In the oral contraceptive group, the effectiveness rate was higher than 80% at 1- and 3-months post-treatment and higher than 90% at 6 months. In the levonorgestrel intrauterine system group, the effectiveness rates were 58.06%, 54.84%, and 61.29% at 1, 3, and 6 months of treatment, respectively. Oral contraceptives were more effective than the levonorgestrel intrauterine system in treating intermenstrual bleeding caused by uterine niche (p < 0.05).

Intra-operative Diagnosis of Lower Segment Scar Dehiscence in a Second Gravida After One Previous Lower Segment Cesarean Section: Should We Advocate for Routine Antenatal Uterine Scar Thickness Testing?

Background: Uterine dehiscence is a separation of uterine musculature with intact uterine serosa. It can be encountered at the time of cesarean delivery, suspected on obstetric ultrasound or diagnosed in-between pregnancies. The antenatal diagnosis may occasionally elude the Obstetricians. This particular case demonstrates an intra-operative diagnosis of uterine dehiscence with missed antenatal ultrasound diagnosis in an asymptomatic woman. Case presentation: She was a 32-year-old Nigerian second gravida who booked for antenatal care at 32 weeks of gestation following a referral from her attending Obstetrician from a neighboring state due to relocation. She had 3 antenatal visits and 2 antenatal ultrasound investigations without uterine scar thickness report. She subsequently had elective Cesarean section (CS) at a gestational age of 38 weeks plus 2 days due to persistent breech presentation on a background of a previous lower segment CS scar. There was no previous uterine curettage prior to or after the previous lower segment CS scar and there was no labor pains prior to the elective CS. The surgery was successful with intra-operative findings of moderate intra parietal peritoneal adhesions with rectus sheath and obvious uterine dehiscence along the line of the previous CS scar. The fetal outcomes were normal. Immediate post-operative condition was satisfactory and the woman was discharged on a third-day post operation. Conclusion: Obstetricians are charged to maintain a high index of suspicion when managing pregnant women with history of emergency CS in order to avert the adverse consequences of uterine rupture from asymptomatic uterine dehiscence. Based on this report, it may be useful to routinely assess the lower uterine segment scar of women with previous emergency CS using the available ultrasound facilities. However, more studies are needed before advocating for routine antenatal uterine scar thickness testing following emergency lower segment CS in low and middle-income settings.

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.