|Year : 2018 | Volume
| Issue : 1 | Page : 111-114
Influence of the number of previous cesarean sections on lower uterine segment state
Mohamed K Alosh, Mohamed A Farag, Samah B Omar
Department of Gynecology and Obstetric, Benha Teaching Hospital, Benha, Egypt
|Date of Submission||14-Jul-2017|
|Date of Acceptance||10-Oct-2017|
|Date of Web Publication||28-Feb-2018|
Samah B Omar
Department of Gynecology and Obstetric, El-Azhar University, Benha Teaching Hospital, Benha, 13511
Source of Support: None, Conflict of Interest: None
Background The present study aims to determine the influence of the number of previous cesarean section (CS) on the lower uterine segment (LUS).
Patients and methods The study included 200 pregnant women divided equally into four groups: group I included 50 women with one previous CS, group II included 50 women with two previous CS, group III included 50 women with three previous CS, and group IV included 50 women with no previous uterine operation as a control group. The women studied were subjected to the following: a careful assessment of history, a thorough clinical and obstetrical examination, and ultrasonographic assessment of the LUS below, at, and above the CS scar to evaluate thickness.
Results The results showed that women with previous CSs have significantly thinner LUS compared with the group of pregnant women without scars. With increasing numbers of previous CSs, the LUS thickness decreases, but the difference is not statistically significant.
Conclusion Women with more CR had thinner LUS scars and more scar defects.
Keywords: cesarean rate, cesarean section, lower uterine segment
|How to cite this article:|
Alosh MK, Farag MA, Omar SB. Influence of the number of previous cesarean sections on lower uterine segment state. Benha Med J 2018;35:111-4
|How to cite this URL:|
Alosh MK, Farag MA, Omar SB. Influence of the number of previous cesarean sections on lower uterine segment state. Benha Med J [serial online] 2018 [cited 2018 Aug 21];35:111-4. Available from: http://www.bmfj.eg.net/text.asp?2018/35/1/111/226409
| Introduction|| |
There has been an increase in the rates of cesarean births worldwide over the last two decades. The performance of multiple cesarean section (CS) exposes women to greater risks of complications; furthermore, the risk of complications increases with each subsequent CS according to the study carried out in 2011 .
Several methods ranging from postoperative echographic evaluation of uterine wound, interval hysterography, and magnetic resonance imaging to amniography have been used to assess the integrity of scarred lower uterine segment (LUS) in a study carried out in 2007 .
However, in a recent study, carried out in 2013, it was found that sonographic evaluation of the LUS may be a noninvasive, reproducible, and safe technique for defining the risk of uterine dehiscence, with a sensitivity of 100% and a specificity of 85% .
| Aim|| |
The present study aims to determine the influence of the number of previous CS on the LUS and decreased complications of repeated CS.
| Patients and methods|| |
The present study aims to determine the influence of the number of previous CS on the LUS state at the time of elective lower segment CS. This study was carried out at Benha University Hospital at the Clinic of Gynecology and Obstetrics from January 2014 to January 2017.
This was a prospective observational cross section study. The study included 200 pregnant women divided equally into four groups: group I included 50 women with one previous CS, group II included 50 women with two previous CS, group III included 50 women with three previous CS, and group IV included 50 women with no previous uterine operation as a control group. The inclusion criterion was singleton pregnant women 37 or more gestational weeks.
Women were excluded if they had multifetal pregnancies, placenta previa, or low-lying placenta, as well as pregnant women in the active delivery phase. The women studied were subjected to the following: a careful assessment of history, a thorough clinical and obstetrical examination, and ultrasonographic assessment of the LUS below, at, and above the CS scar to evaluate thickness. An intraoperative assessment of LUS was also performed.
LUS was classified as follows:
- Well developed: class I.
- Thin but without visible bulging of membrane inside: class II.
- Partial scar defect dehiscence: class III.
- Complete scar dehiscence incomplete rupture: class IV.
Classes III and IV with scar defects were considered positive findings.
Data obtained from the present study were computed using SPSS versions 17 under the platform of Microsoft Windows 7 (SPSS Inc., Chicago, Illinois, USA). Continuous data were described as mean±SD, whereas categorical data were described as count and percentage. Comparison of continuous data was performed utilizing a one-way analysis of variance test, whereas categorical data were determined using the χ2-test. A P value less than 0.05 was considered statistically significant.
| Results|| |
The results of the present study are shown in [Table 1],[Table 2],[Table 3].
|Table 1 Comparison between the groups studied in terms of the basic data|
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|Table 2 Comparison between the groups studied in ultrasound scar thickness and scar defects|
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|Table 3 Comparison between the groups studied in terms of lower uterine segment operative findings|
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| Discussion|| |
In the present study, group III had significantly older age due to their higher rate of CS operations. No statistically significant differences were found between the groups studied in gestational age and BMI. Comparison between the studied groups in terms of ultrasound (US) scar thickness and scar defects showed significantly higher US scar thickness in patients with fewer CS operations compared with their counterparts with more CS operations of any frequency.
Women with more CS had more deficient scars compared with women with fewer CS operations. Moreover, there was a significantly higher frequency of abnormal LUS operative findings in patients with more CS operations compared with their counterparts with fewer CS operations.
This is in agreement with a study carried out by Ofili-Yebovi et al. , examined that the sonographic features of transverse lower segment uterine CS scars to identify the factors associated with scar deficiency. In their study, increased frequency of CS was associated with decreased LUS scar thickness and higher frequency of deficient scars. In addition, a study was carried out in 2009  that aimed to determine the prevalence of clinical symptoms associated with cesarean scar defects, and to determine the association between the size of these defects, clinical complaints, uterine position, and a history of multiple CSs.
In their study, women who had undergone multiple CSs tended to have larger scar defects (in width and depth) than those who had undergone a single CS. Moreover, the study Osser et al.  concluded that CS scars can be detected reliably by US imaging. Myometrial thickness at the level of the isthmus uteri decreases with the number of CSs and the frequency of large scar defects increases .
Similarly, a study by Kushtagi and Garepalli  found that women with repeat CS had significantly lower LUS thickness compared with women with previous vaginal delivery. In the current study, the correlation between CS scar thickness and the individual groups did not show statistical significance. However, there were significant inverse relations between women’s age and CS scar thickness. This can be attributed to the increased frequency of CS with increasing age of women.
However, a study by Sanlorenzo et al.  evaluated the LUS thickness through transvaginal sonography (TVS) in late preterm and full-term pregnancies with a single previous CS and found a significant association between LUS thickness and gestational age. This can be explained by the fact that this study, in contrast to ours, included preterm CS deliveries. In terms of the relation between intraoperative findings and preoperative US assessment, our study found a significantly higher frequency of deficient scars at US in women with abnormal operative scars.
In addition, significantly lower LUS thicknesses were found in patients with abnormal findings compared with those with normal data. This in agreement with the study by Jastrow et al. , which studied the diagnostic accuracy of sonographic measurements of the LUS thickness near term in predicting uterine scar defects in women with previous CS through a systematic review.In their study, it was concluded that sonographic LUS thickness is a strong predictor for uterine scar defects in women with previous CS.
Our data are also in agreement with the study by Sharma et al.  estimated that the risk of uterine dehiscence in women with previous CS by comparing the thickness of the LUS and myometrium with transabdominal sonography (TAS) and TVS. In their case–control study, in 100 pregnant women scheduled for elective CS (with or without previous CS: group I and group II, respectively), the thickness of LUS and myometrium was measured sonographically (TAS and TVS).
Intraoperatively, LUS was graded (grades I–IV) and its thickness was measured with calipers. The primary outcome of the study was the correlation between echographic measurements (TAS and TVS) and features of LUS (grades I–IV) at the time of CS. The secondary outcomes were correlations between myometrial thickness, number of previous CS, and interdelivery interval with LUS (grades I–IV). Sonographic measurements of LUS and myometrium were significantly different between the two groups (both TAS and TVS, P=0.000 each).
| Conclusion|| |
Women with more CR had thinner LUS scars and more scar defects.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Madaan M, Grobman WA, Lai Y, Landon MB, Leveno KJ, Rouse DJ et al.
Development of a normogram for prediction of vaginal birth after caesarean delivery. Obstet Gynecol 2007; 109:806–812.
Kushtagi P, Garepalli S. Sonographic assessment of lower uterine segment at term in women with previous cesarean delivery. Arch Gynecol Obstet 2011; 283:455–459.
Gizzo S, Zambon A, Saccardi C. Effective anatomical and functional status of the lower uterine segment at term: estimating the risk of uterine dehiscence by ultrasound. Fertil Steril 2013; 99:496–501.
Ofili-Yebovi D, Ben-Nagi J, Sawyer E, Yazbek J, Lee C, Gonzalez J, Jurkovic D. Deficient lower-segment cesarean section scars: prevalence and risk factors. Ultrasound Obstet Gynecol 2008; 31:72–77.
Wang CB, Chiu WW, Lee CY. Cesarean scar defect: correlation between cesarean section number, defect size, clinical symptoms and uterine position. Ultrasound Obstet Gynecol 2009; 34:85–89.
Osser OV, Jokubkiene L, Valentin L. High prevalence of defects in cesarean section scars at transvaginal ultrasound examination. Ultrasound Obstet Gynecol 2009; 34:90–97.
Sanlorenzo O, Farina A, Pula G, Zanello M, Pedrazzi A, Martina T et al.
Sonographic evaluation of the lower uterine segment thickness in women with a single previous cesarean section. Minerva Ginecol 2013; 65:551–555.
Jastrow N, Chaillet N, Roberge S, Morency AM, Lacasse Y, Bujold E. Sonographic lower uterine segment thickness and risk of uterine scar defect: a systematic review. J Obstet Gynaecol Can 2010; 32:321–327.
Sharma C, Surya M, Soni A, Soni PK, Verma A, Verma S. Sonographic prediction of scar dehiscence in women with previous cesarean section. J Obstet Gynaecol India 2015; 65:97–103.
[Table 1], [Table 2], [Table 3]