Zakherah, M., Mohamed, A., Rageh, A. M., & Abdel-Aleem, M. A. (2024). Navigating uterine niche 360 degree: a narrative review. Middle East Fertility Society journal, 29(1). https://doi.org/10.1186/s43043-024-00185-7
Zakherah M, Mohamed A, Rageh AM, Abdel-Aleem MA. Navigating uterine niche 360 degree: a narrative review. Middle East Fertil Soc J. 2024;29(1). doi:10.1186/s43043-024-00185-7
Zakherah, Mahmoud, et al. "Navigating uterine niche 360 degree: a narrative review." Middle East Fertility Society journal, vol. 29, no. 1, 2024.
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The increasing prevalence of cesarean section (CS) deliveries globally has sparked apprehension regarding potential long-term complications, notably the emergence of uterine niches. CS results in a scar that in certain patients, inadequate healing of that scar results in the development of a uterine niche. While most small niches show no symptoms, large cesarean scar niches in nonpregnant women can give rise to cesarean scar disorder syndrome. This syndrome is characterized by abnormal uterine bleeding, dysmenorrhea, and secondary infertility. In pregnant women, the presence of substantial niches may be linked to potentially life-threatening complications, including cesarean scar dehiscence, uterine rupture, placenta accreta spectrum disorders, placenta previa, and cesarean scar ectopic pregnancy.
Main Body
Given the potential dangers associated with uterine niche occurrence, numerous studies in recent years have delved into the concept of cesarean scar niche, exploring its risk factors, diagnostic approaches, and treatment options. Various diagnostic modalities, such as twoor three-dimensional transvaginal ultrasonography, twoand three-dimensional sono-hysterography, hysterosalpingography, hysteroscopy, or magnetic resonance imaging, can be employed to detect uterine niches. However, none of these diagnostic methods is universally accepted as the “gold standard,” and there remains a lack of unequivocal guidelines on certain aspects related to the diagnosis of cesarean scar niche. These niches, characterized by hypoechoic regions within the myometrium at the site of a previous CS scar, pose diagnostic complexities and provoke inquiries into their prevalence, factors influencing their development, clinical presentations, and appropriate therapeutic approaches.
Conclusion
As CS rates rise, this review aims to understand and address uterine niches and mitigate their impact on maternal health and reproductive outcomes.
We report the complications observed after transvaginal oocyte retrieval guided by ultrasound in 7,098 IVF cycles. The frequency of severe complications in our patients was 0.08%, of which four cases were intraperitoneal bleeding (0.06%) and two were cases of ovarian abscess (0.003%).
Kulshrestha V et al., 2021·J Obstet Gynaecol India·Free full text on PubMed Central
Uterine niche is one of the emerging complications of caesarean section. With rising caesarean rates, the caesarean-related iatrogenic complications are also on the rise. These include placenta accreta, scar ectopic pregnancy and uterine niche which is a newer entity being described in the recent literature. Uterine niche, also described as uterine isthmocele, caesarean scar defect and diverticulum, is an iatrogenic defect in the myometrium at the site of previous caesarean scar due to defective tissue healing. Patients may have varied symptoms including abnormal uterine bleeding, post-menstrual spotting and infertility, though many women may be asymptomatic and diagnosed incidentally. Diagnosis is made radiologically by transvaginal sonography, saline instillation sonohysterography or magnetic resonance imaging. Occurrence of niche may be prevented by using correct surgical technique during caesarean. Patients may be managed medically; however, subfertility and persistent symptoms may require surgical correction either by hysteroscopic resection or transabdominal or transvaginal repair. This mini-review comprehensively covers the potential risk factors, clinical presentation, diagnosis and management of this increasingly encountered condition due to rising caesarean rates.
Kremer TG et al., 2019·Rev Assoc Med Bras (1992)·Free to read
An isthmocele, a cesarean scar defect or uterine niche, is any indentation representing myometrial discontinuity or a triangular anechoic defect in the anterior uterine wall, with the base communicating to the uterine cavity, at the site of a previous cesarean section scar. It can be classified as a small or large defect, depending on the wall thickness of the myometrial deficiency. Although usually asymptomatic, its primary symptom is abnormal or postmenstrual bleeding, and chronic pelvic pain may also occur. Infertility, placenta accrete or praevia, scar dehiscence, uterine rupture, and cesarean scar ectopic pregnancy may also appear as complications of this condition. The risk factors of isthmocele proven to date include retroflexed uterus and multiple cesarean sections. Nevertheless, factors such as a lower position of cesarean section, incomplete closure of the hysterotomy, early adhesions of the uterine wall and a genetic predisposition may also contribute to the development of a niche. As there are no definitive criteria for diagnosing an isthmocele, several imaging methods can be used to assess the integrity of the uterine wall and thus diagnose an isthmocele. However, transvaginal ultrasound and saline infusion sonohysterography emerge as specific, sensitive and cost-effective methods to diagnose isthmocele. The treatment includes clinical or surgical management, depending on the size of the defect, the presence of symptoms, the presence of secondary infertility and plans of childbearing. Surgical management includes minimally invasive approaches with sparing techniques such as hysteroscopic, laparoscopic or transvaginal procedures according to the defect size.
The objective of this study was to evaluate the prevalence of cesarean scar defects and its clinical manifestations in reproductive-aged women. We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement using keywords of "cesarean scar defect, uterine scar defect, uterine diverticulum niche, isthmocele, pouch, or sacculation" and their combination. Thirty-two trials met the inclusion criteria. Cesarean scar defects are commonly found on ultrasound examination (24%-88%). Their presence could be asymptomatic or related to postmenstrual spotting, postmenstrual bleeding, or infertility. The prevalence of this condition is related to the number of cesarean deliveries. Hysteroscopic repair of a cesarean scar defect or isthmoplasty is associated with an improvement in uterine bleeding in 59% to 100% of cases and a pregnancy rate of 77.8% to 100%. An improvement in uterine bleeding after vaginal repair occurred in 89% to 93.5% of cases. Laparoscopic repair led to uterine bleeding improvement in 86% of cases and a pregnancy rate of 86%. The association between cesarean scar defect and infertility, pelvic pain, and dysmenorrhea require more studies. Treatment of uterine scar defects should be performed after eliminating other causes of postmenstrual bleeding or infertility. Hysteroscopic isthmoplasty appears to be the most popular treatment. However, in the absence of randomized trials, the efficacy of different surgical approaches remains to be seen. Until we have concrete evidence, the treatment should be reserved for selective cases.
Klein Meuleman SJM et al., 2023·JAMA Netw Open·Free full text on PubMed Central
Approximately 60% of women develop a uterine niche after a cesarean delivery (CD). A niche is associated with various gynecological symptoms including abnormal uterine bleeding, pain, and infertility, but there is little consensus in the literature on the distinction between the sonographic finding of a niche and the constellation of associated symptoms. To achieve consensus on defining the clinical condition that constitutes a symptomatic uterine niche and agree upon diagnostic criteria and uniform nomenclature for this condition.
Design, Setting, and A consensus based modified electronic Delphi (eDelphi) study, with a predefined Rate of Agreement (RoA) of 70% or higher. Experts were selected according to their expertise with niche-related consultations, publications, and participation in expert groups and received online questionnaires between November 2021 and May 2022. Definition, nomenclature, symptoms, conditions to exclude, and diagnostic criteria of an illness caused by a symptomatic uterine niche. In total, 31 of the 60 invited experts (51.7%) participated, of whom the majority worked in university-affiliated hospitals (28 of 31 [90.3%]), specialized in benign gynecology (20 of 31 [64.5%]), and worked in Europe (24 of 31 [77.4%]). Three rounds were required to achieve consensus on all items. All participants underlined the relevance of a new term for a condition caused by a symptomatic niche and its differentiation from a sonographic finding only. Experts agreed to name this condition cesarean scar disorder, defined as a uterine niche in combination with at least 1 primary or 2 secondary symptoms (RoA, 77.8%). Defined primary symptoms were postmenstrual spotting, pain during uterine bleeding, technical issues with catheter insertion during embryo transfer, and secondary unexplained infertility combined with intrauterine fluid. Secondary symptoms were dyspareunia, abnormal vaginal discharge, chronic pelvic pain, avoiding sexual intercourse, odor associated with abnormal blood loss, secondary unexplained infertility, secondary infertility despite assisted reproductive technology, negative self-image, and discomfort during participation in leisure activities. Consensus was also achieved on certain criteria that should be met and conditions that should be excluded before making the diagnosis. Conclusions and Relevance: In this modified Delphi study, a panel of 31 international niche experts reached consensus for the constellation of symptoms secondary to a uterine niche and named it cesarean scar disorder.
Uterine and Pelvic Conditions › Acquired Uterine Conditions › Cesarean Scar Defect · Diagnostics › Tubal and Uterine Imaging › Sonohysterography · Birth and Delivery › Cesarean Birth › Cesarean Recovery and Scar
Abdulrahman M. Rageh, Mahmoud Zakherah
A Rageh, M Zakherah
DOI 10.1186/s43043-024-00185-7 10.1186/s43043-024-00185-7 Zakherah et al. 2024, Zakherah 2024
Cite this article
Zakherah, M., Mohamed, A., Rageh, A. M., & Abdel-Aleem, M. A. (2024). Navigating uterine niche 360 degree: a narrative review. Middle East Fertility Society journal, 29(1). https://doi.org/10.1186/s43043-024-00185-7
Zakherah M, Mohamed A, Rageh AM, Abdel-Aleem MA. Navigating uterine niche 360 degree: a narrative review. Middle East Fertil Soc J. 2024;29(1). doi:10.1186/s43043-024-00185-7
Zakherah, Mahmoud, et al. "Navigating uterine niche 360 degree: a narrative review." Middle East Fertility Society journal, vol. 29, no. 1, 2024.
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