Clinical trial NCT03787381: Uterine Niche After Cesarean Section
Official title: Factors Influencing the Development of Uterine Niche After Cesarean Delivery
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Uterine Scar From Previous Cesarean Delivery (Diagnosis)
Keywords: cesarean section, niche, uterine scar defect
Lead sponsor: Sheba Medical Center
Sponsor class: OTHER_GOV
First posted: 2018-12-26
Enrollment: 282
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 42
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: In the past decade several articles have described a defect that can be seen on ultrasound at the site of cesarean delivery scar, known as a 'niche' .An incompletely healed scar is a long-term complication of cesarean delivery and is associated with symptoms such as postmenstual spotting, dysmenorrhoea, chronic pelvic pain dyspareunia and subfertility. This study aimes to evaluate the prevalence of niche in a large cohort study after long term follow up since operation, and characterize the risk factors for its development and for symptoms to appear.

Detailed description: As the rate of cesarean deliveries continues to increase, concern regarding the association between delivery by cesarean section and long-term maternal morbidity has been growing . In the past decade several articles have described a defect that can be seen on ultrasound at the site of the cesarean delivery scar, known as a 'niche' .A 'niche' describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous cesarean delivery . An incompletely healed scar is a long-term complication of cesarean delivery and is associated with symptoms such as postmenstual spotting, dysmenorrhoea, chronic pelvic pain dyspareunia and subfertility.

The reported prevalence of a niche in non-pregnant women varies depending on the criteria used to define a niche, the time of evaluation since operation, method of detection, and study population. Osser et al. used the definition 'any visible defect' , Bij de Vaate et al. used 'any indentation of at least 1 mm and van der Voet used a cut-off level of 2 mm, however, consensus on the exact cut-off levels is lacking. As approximate evaluation to the operation, the prevalence reported is higher, as early scanning may facilitate the recognition of the location of the caesarean delivery scar in the uterine wall due to incomplete scar healing, with no definition of the most appropriate time since operation. Commonly used methods to evaluate the presence of a niche are trans vaginal ultrasound, sonohysterography and hysteroscopy with detection rate of approximately \~50% of women with previous cesarean section in all methods with no definition of the gold standard.

The aim of this study in to evaluate the prevalence of niche in a large cohort study after long term follow up since operation and characterize the risk factors for its development and for symptoms to appear.

Eligibility criteria: Inclusion Criteria:

* Women after cesarean delivery
* Minimum interval of 3 months since operation

Exclusion Criteria:

* Uterine scar other than low segment cesarean section ( s/p myomectomy, S/p T scar)
* Morbidly adherent placenta during pregnancy
* Cesarean hysterectomy
* Uterine anomaly

Primary outcomes:
measure: Diagnosis of uterine niche
timeFrame: Estimated time of two years
Secondary outcomes:
Other outcomes:
Locations:
city: Ramat Gan
country: Israel
facility: Sheba Medical Center
Study officials:
affiliation: Sheba Medical Center, Tel-Hashomer
name: Aya Mohr Sasson, M.D
role: PRINCIPAL_INVESTIGATOR
References:
citation: van der Voet LF, Bij de Vaate AM, Veersema S, Brolmann HA, Huirne JA. Long-term complications of caesarean section. The niche in the scar: a prospective cohort study on niche prevalence and its relation to abnormal uterine bleeding. BJOG. 2014 Jan;121(2):236-44. doi: 10.1111/1471-0528.12542.
citation: Naji O, Abdallah Y, Bij De Vaate AJ, Smith A, Pexsters A, Stalder C, McIndoe A, Ghaem-Maghami S, Lees C, Brolmann HA, Huirne JA, Timmerman D, Bourne T. Standardized approach for imaging and measuring Cesarean section scars using ultrasonography. Ultrasound Obstet Gynecol. 2012 Mar;39(3):252-9. doi: 10.1002/uog.10077.
citation: Roberge S, Boutin A, Chaillet N, Moore L, Jastrow N, Demers S, Bujold E. Systematic review of cesarean scar assessment in the nonpregnant state: imaging techniques and uterine scar defect. Am J Perinatol. 2012 Jun;29(6):465-71. doi: 10.1055/s-0032-1304829. Epub 2012 Mar 7.
citation: Vervoort AJ, Uittenbogaard LB, Hehenkamp WJ, Brolmann HA, Mol BW, Huirne JA. Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development. Hum Reprod. 2015 Dec;30(12):2695-702. doi: 10.1093/humrep/dev240. Epub 2015 Sep 25.
citation: Wang CB, Chiu WW, Lee CY, Sun YL, Lin YH, Tseng CJ. Cesarean scar defect: correlation between Cesarean section number, defect size, clinical symptoms and uterine position. Ultrasound Obstet Gynecol. 2009 Jul;34(1):85-9. doi: 10.1002/uog.6405.
citation: Osser OV, Jokubkiene L, Valentin L. Cesarean section scar defects: agreement between transvaginal sonographic findings with and without saline contrast enhancement. Ultrasound Obstet Gynecol. 2010 Jan;35(1):75-83. doi: 10.1002/uog.7496.