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

Emerging data on diagnosis and management of uterine isthmoceles: a rapid review

PURPOSE OF REVIEW

With a rising number of cesarean sections, the prevalence of uterine isthmoceles is increasing. We performed a rapid review to assess the most recent data on the diagnosis and management of uterine isthmoceles over the past 18 months to identify current trends and directions for continued research.

RECENT FINDINGS

A comprehensive search was conducted in PubMed (NLM), Embase (Ovid), CINAHL (EBSCOhost) to find English written articles discussing the diagnosis or management of uterine isthmoceles published in the previous 18 months. Data extraction was performed on one hundred articles that met inclusion criteria.

SUMMARY

This rapid review highlights agreement regarding diagnostic methods, symptoms, and recommended treatment paths for patients with symptomatic uterine niches. However, the diversity in definitions hampers the capacity to formulate detailed conclusions regarding the features of uterine niches and their impact on women's health.

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.

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.

Influence of Cesarean Section on Postpartum Fertility and Dysmenorrhea: A Retrospective Cohort Study in Japan

Objective

To investigate the association between cesarean section (CS) and postpartum fertility and dysmenorrhea using data from a Japanese insurance registry.

Methods

This retrospective cohort study used a data set of patients registered between 2007 and 2021 in an insurance registry comprising specific employee-based health insurance companies in Japan. Of those data sets, we included data from participants who had their first recorded childbirth between 2014 and 2018. The exclusion criteria were any prior deliveries, dysmenorrhea, or complications that would affect the next pregnancy or postpartum dysmenorrhea since 2007. The occurrence of subsequent childbirth and postpartum dysmenorrhea until 2021 was compared between the CS and vaginal delivery (VD) groups using the log-rank test and Cox proportional hazards model with stratification according to age and age matching.

Results

This study included 25,984 (5,926 after age matching) and 5,926 participants in the VD and CS groups, respectively. After age matching, the rate of subsequent childbirth was 18.3% and 16.3%, and the rate of postpartum dysmenorrhea was 6.5% and 7.8% in the VD and CS groups, respectively. There were fewer subsequent childbirths in the CS group than in the VD group after age matching in the stratified Cox proportional hazards model (hazard ratio [HR] 95% confidence interval [CI]: 0.86 [0.79-0.94]). The CS group had a significantly higher risk of dysmenorrhea (HR [95% CI]: 1.18 [1.03-1.36]).

Conclusions

Although confounding might be existing, our study suggests that CS might be associated with decreased postpartum fertility and increased dysmenorrhea. The medical indications for CS should be carefully determined; post-CS women should be meticulously followed up.