Cesarean scar defect: a prospective study on risk factors.

BACKGROUND: Cesarean scar defect (isthmocele) is a known complication after cesarean delivery. It has become more common due to a rising cesarean delivery rate. Isthmocele has been associated with various gynecological and obstetric problems such as uterine rupture, cesarean scar pregnancy, and bleeding disorders. OBJECTIVE: We sought to prospectively investigate factors associated with the risk for isthmocele assessed by sonohysterography. STUDY DESIGN: A prospective observational cohort study was conducted in 401 nonpregnant women who were recruited within 3 days of cesarean delivery. Women were evaluated with sonohysterography 6 months after cesarean delivery to detect a possible isthmocele. The ultrasonographer was blinded to any clinical information. The main outcome measure was the presence of isthmocele. Type of surgery (elective vs emergency), maternal background variables, and factors related to pregnancy, labor, and postoperative recovery were analyzed in relation to isthmocele. A logistic regression model was used to assess independent risk factors from univariate analysis. RESULTS: In all, 371 women were examined with sonohysterography resulting in a follow-up rate of 92.5%. The prevalence of isthmocele was 45.6%. Independent risk factors for isthmocele development were a history of gestational diabetes (odds ratio, 1.73; 95% confidence interval, 1.02-2.92; P = .042), previous cesarean delivery (odds ratio, 3.14; 95% confidence interval, 1.90-5.17; P < .001), and advanced maternal body mass index (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = .012). Every additional unit of body mass index increased the risk of isthmocele by 6%. In the subgroup of emergency cesarean delivery, longer duration of active labor increased the risk for isthmocele (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = .032). There was no statistically significant difference in prevalence between the groups of elective and emergency cesarean delivery (P = .898). CONCLUSION: Based on sonohysterographic examination, maternal body mass index, gestational diabetes, and previous cesarean deliveries are associated with an increased risk for incomplete healing of the uterine incision.

Comparison of transvaginal ultrasound and saline contrast sonohysterography in evaluation of cesarean scar defect: a prospective cohort study.

INTRODUCTION: The aim of this study was to investigate the prevalence of post-cesarean isthmocele and to measure agreement between transvaginal ultrasonography and saline contrast sonohysterography in assessment of isthmocele. MATERIAL AND METHODS: A prospective observational cohort study was carried out at Tampere University Hospital, Finland. Non-pregnant women delivered by cesarean section (n = 371) were examined with transvaginal ultrasonography (TVUS) and sonohysterography (SHG) six months after cesarean section. The main outcome measure was the prevalence of isthmocele using TVUS and SHG. Secondary outcome measures were characteristics of isthmocele. RESULTS: In all, 371 women were included. The prevalence of isthmocele was 22.4% based on TVUS and 45.6% based on SHG. Sensitivity and specificity for TVUS was 49.1 and 100%, respectively, when compared with SHG. Therefore, half of the defects (50.9%) diagnosed with SHG remained undiagnosed with TVUS. Bland-Altman analysis showed an underestimation of 1.1 mm (range 0.00-7.90) for TVUS compared with SHG, with 95% limits of agreement from -1.9 to 4.1 mm. CONCLUSIONS: This methodological study provides confirmatory data that TVUS and SHG are not in good agreement in the isthmocele diagnostics and the use of only TVUS may lead to an underestimation of the prevalence of isthmocele. Thus, SHG should be considered as a method of choice in diagnostics of isthmocele.