JOURNAL OF EVIDENCE BASED MEDICINE AND HEALTHCARE

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2020 Month : September Volume : 7 Issue : 36 Page : 1976-1979.

Retrospective Study of Incidence and Risk Factors of Uterine Scar Dehiscence Identified at Repeat Caesarean Section

Anitha N.1, Kaligotla Deepika2, Prathibha S.D.3

1Department of Obstetrics and Gynaecology, Dr. B.R. Ambedkar Medical College, Bangalore, Karnataka, India. 2Department of Obstetrics and Gynaecology, Dr. B.R. Ambedkar Medical College, Bangalore, Karnataka, India. 3Department of Obstetrics and Gynaecology, Dr. B.R. Ambedkar Medical College, Bangalore, Karnataka, India.

Corresponding Author

Dr. Prathibha S.D., No – 22, AECS Layout, 2nd Main, 2nd Stage, Ashwath Nagar, Bangalore - 566094, Karnataka, India.
Email : prathibhasd67@gmail.com

Abstract

Background

Women with previous caesarean section are at increased risk of associated morbidities such as uterine scar dehiscence, scar rupture, maternal and perinatal morbidity and mortality. This study was designed to explore the incidence of uterine scar dehiscence among women undergoing repeat caesarean section and to investigate the risk factors associated with this condition in our obstetric population.

 

Methods

A record based retrospective study of 5 years (June 2014 to May 2019) was conducted in the Department of Obstetrics and Gynaecology, Dr. B.R. Ambedkar Medical College and Hospital. All women with previous lower segment Caesarean section undergoing repeat Caesarean section were included in the study. Operative data was collected from OT Register and parturition book using a structured questionnaire containing general details, comorbidities, current pregnancy details or complications, risk factors and neonatal outcomes. Data was entered into Microsoft Excel data sheet and was analysed using SPSS 22 version software. Categorical data was represented in the form of frequencies and proportions. Chi - square test and Independent t test were the tests of significance.

 

Results

In this study incidence of scar dehiscence was 8.1 %. Among those with preterm delivery < 37 weeks, 76.5 % had scar dehiscence, among those with tertiary caesarean delivery 70 % had scar dehiscence and among those with inter delivery interval < 24 months, 84.6 % had scar dehiscence. Among those with Apgar < 7 at 5 min, 100 % had scar dehiscence, among those with NICU admission, 18.1 % had scar dehiscence. There was no significant difference between single or double layer closure of uterine incision.

 

Conclusions

Study concludes that preterm delivery, tertiary caesarean delivery and inter delivery interval < 24 months were significantly associated with uterine scar dehiscence.

 

Keywords

Uterine Scar Dehiscence, Repeat Caesarean Section, Risk Factors, Preterm Delivery, Tertiary Caesarean Delivery

Background

Lower Segment Caesarean Section (LSCS) is one of the most frequent surgical procedures done in the department of obstetrics and is certainly one of the oldest operations.1 Ours being a referral institute, Lower Segment Caesarean Section constitutes to 35-38% of all deliveries. All women with Previous Caesarean Section undergo Repeat Caesarean Section at our institute.

The leading maternal indication for Caesarean delivery was previous caesarean section (34 %).1 Eighty to ninety percent of women with previous CD are delivered by Elective Repeat Caesarean Delivery (ERCD) in subsequent pregnancy.2

Women with Previous Caesarean Section are at increased risk of associated morbidities such as uterine scar dehiscence, scar rupture, increased maternal and perinatal morbidity and mortality.2

Uterine rupture is classified as Complete when all the layers of the uterine wall are separated, or Incomplete when the uterine muscle is separated but the visceral peritoneum is intact. Incomplete uterine rupture is referred to as.

Uterine Scar Dehiscence (USD). The greatest risk factor for either form of rupture is prior caesarean delivery3. Scar dehiscence means asymptomatic separation of the scar without involving the peritoneal coat and without symptoms. Uterine scar dehiscence refers to an incomplete uterine scar disruption where the serosa remains intact and the foetus, placenta and umbilical cord remain contained within the uterine cavity. Uterine scar rupture refers to complete giving away of the Uterine scar and the foetus and placenta lying in the abdominal cavity.

The precise definition of uterine scar dehiscence considered in the study was muscular disruption of any size with intact serosa. Thinning of the lower uterine segment of any degree was not considered as dehiscence. This study was designed to explore the incidence of uterine scar dehiscence among women undergoing repeat caesarean section and to investigate the risk factors associated with this condition in our obstetric population.

We wanted to determine the incidence of uterine scar dehiscence and assess the risk factors associated with uterine scar dehiscence among women undergoing repeat Caesarean section.

Methods

This is a record based retrospective study conducted in the Department of Obstetrics and Gynaecology, Dr. B.R. Ambedkar Medical College and Hospital over a period of 5 years from June 2014 to May 2019. All women with previous lower segment Caesarean section undergoing repeat Caesarean section were included in the study. Sampling was done by universal sampling method during the study period. Patients who had undergone classical caesarean section, patients with placenta previa, abnormally invasive placenta and patients whose complete data was not available were excluded from the study.

After obtaining Internal Ethical Committee approval, Operative data collected from OT Register and Parturition book in the Department of Obstetrics and Gynaecology at Dr. B R Ambedkar Medical College and Hospital for a period of 5 years [June 2014 to May 2019]. Data was collected using a structured questionnaire consisting general details, Co-morbidities, Current pregnancy details or complications, risk factors and neonatal outcomes were collected from the records.

 

Statistical Methods

Data was entered into Microsoft Excel data sheet and was analysed using SPSS 22 version software. Categorical data was represented in the form of Frequencies and proportions. Chi-square test or Fischer’s exact test (for 2 x 2 tables only) was used as test of significance for qualitative data. Continuous data was represented as mean and standard deviation. Independent t test was used as test of significance to identify the mean difference between two quantitative variables. p value <0.05 was considered as statistically significant after assuming all the rules of statistical tests.

Results

A record based retrospective study was conducted on all patients undergoing Repeat Caesarean Section fulfilling the inclusion criteria during the study period from June 2014 to May 2019. In the study period, 764 women underwent Repeat Caesarean section at our institute. In the present study, 62 women had scar dehiscence accounting for incidence of 8.1 %. There was no statistically significant difference in maternal age and birth weight between those with and without scar dehiscence. In the study among those with Scar dehiscence, 4.8 % had Gestational Diabetes Mellitus (GDM), 1.6 % had Hypertensive Disorders of Pregnancy (HDP) and 0 % had preterm birth in previous pregnancy. There was no significant association between Comorbidity and Scar Dehiscence which was not statistically significant.

In the present study there was no statistically significant association between factors such as Breech presentation at the time of delivery, Twin gestation or patient in labour at the time of delivery with Scar dehiscence. Pain at caesarean scar site at the time of delivery was associated with scar dehiscence in 32.2 % of cases which was statistically significant. In the present study, risk factors like preterm delivery < 37 weeks, Tertiary Caesarean Delivery, inter delivery interval < 24 months were significantly associated with Scar dehiscence. Preterm delivery had 76.5 % association with Scar dehiscence which is statistically significant. Higher incidence of Scar dehiscence was observed among women undergoing Tertiary. Caesarean Delivery (70 %). Inter delivery interval <24 months had 84.6 % association with Scar Dehiscence.

 

 

 

 

Scar Dehiscence

P Value

Yes

No

Count

%

Count

%

GDM

No

59

95.2 %

678

96.6 %

0.562

Yes

3

4.8 %

24

3.4 %

HDP

No

61

98.4 %

675

96.2 %

0.370

Yes

1

1.6 %

27

3.8 %

Previous preterm birth

No

62

100.0 %

701

99.9 %

0.766

Yes

0

0.0 %

1

0.1 %

Breech

No

61

8.1 %

690

91.9 %

0.955

Yes

1

7.7 %

12

92.3 %

Twin gestation

No

62

8.1 %

700

91.9 %

0.674

Yes

0

0.0 %

2

100.0 %

Labour

No

11

5.8 %

178

94.2 %

0.183

Yes

51

8.9 %

524

91.1 %

Pain at caesarean scar site

No

13

2.1 %

599

97.9 %

<0.001*

Yes

49

32.2 %

103

67.8 %

Preterm delivery <37 weeks

No

49

6.6 %

698

93.4 %

<0.001*

Yes

13

76.5 %

4

23.5 %

Tertiary caesarean delivery

No

48

6.5 %

696

93.5 %

<0.001*

Yes

14

70.0 %

6

30.0 %

Inter delivery interval <24 months

No

29

4.0 %

696

96.0 %

<0.001*

Yes

33

84.6 %

6

15.4 %

Table 3. Association between Antenatal Risk Factors in the Present Pregnancy and Scar Dehiscence

 

 

Count

%

Scar Dehiscence

Yes

62

8.1 %

No

702

91.9 %

Table 1. Incidence of Scar Dehiscence

 

 

Scar Dehiscence

P Value

Yes

(n = 62)

No

(n = 702)

Mean

SD

Mean

SD

Mean Maternal age

25.47

3.74

26.75

10.99

0.362

Birth weight (Kg)

2.77

0.366

2.73

0.43

0.545

Table 2. Comparison of Mean Age and Birth Weight

with Regard to Scar Dehiscence

 

 

Scar Dehiscence

P Value

Yes

No

Count

%

Count

%

Double layer closure

No

46

7.8 %

547

92.2 %

0.500

Yes

16

9.4 %

155

90.6 %

Table 4. Previous Caesarean Scar Closure

and Scar Dehiscence

 

In the present study among those with double layer closure of uterine incision, 9.4 % had scar dehiscence and single layer closure of uterine incision, 7.8 % had scar dehiscence. There was no statistically significant association between Single layer or double layer closure of uterine incision and scar dehiscence in next pregnancy.

 

Scar Dehiscence

P Value

Yes

No

Count

%

Count

%

Apgar <7

 at 5 min

No

61

8.0%

702

92.0%

0.001*

Yes

1

100.0%

0

0.0%

Asphyxia neonatorum

No

62

8.1%

702

91.9%

-

NICU admission

No

35

5.7%

580

94.3%

<0.001*

Yes

27

18.1%

122

81.9%

LBW

<2.5 Kg

15

6.1%

231

93.9%

0.159

>2.5 Kg

47

9.1%

471

90.9%

Table 5. Neonatal Outcome and Its Association                             with Scar Dehiscence

 

In the present study among the neonates with Apgar < 7 at 5 min, 100 % had Scar dehiscence. NICU admission was seen in 18.1 % of neonates who had Scar Dehiscence and among those with LBW, 6.1 % had Scar Dehiscence. There was significant association between Apgar < 7 at 5 minutes and NICU admission with Scar Dehiscence.

Discussion

Women with previous caesarean section are at an increased risk of associated morbidities such as uterine scar dehiscence, scar rupture, maternal and perinatal morbidity and mortality. This study was designed to explore the incidence of uterine scar dehiscence among women undergoing repeat caesarean section and to investigate the risk factors associated with this condition in our obstetric population.

In the present study incidence of Uterine Scar dehiscence (USD) was 8.1 %. Incidence of USD reported in the literature, ranges from 0.3 % to 19.4 %.4 The variations in the incidence can be attributed to lack of definition for USD.5,6,7,8,9,10,11

In the present study among those with Preterm delivery <37 weeks [OR: 46.3. 95 % CI: 14.55, 147.3], Tertiary caesarean delivery [OR: 33.83, 95 % CI: 12.45, 91.97] and Inter delivery interval < 24 months [OR: 132, 95 % CI: 51.26, 339.9], were significantly associated with Scar dehiscence. Bashiri et al observed that preterm delivery was an independent risk factor for uterine Scar dehiscence (OR: 1.79, 95 % CI: 1.01 - 3.21, p = 0.048).5 The significant association between preterm delivery and uterine Scar dehiscence may be due to uterine infection/inflammation that may have caused weakness of the uterine scar.

Bashiri et al reported similar finding of significant association between increased number of Caesarean section and scar dehiscence. Wang et al observed larger scar defect among women having more than one previous CD compared to those with only one previous CD.4 This was attributed to having thinner scars in those with higher number of CD.5

Bujold et al observed hat 10.5 % of Scar dehiscence among patients with inter-delivery interval of < 24 months compared to 3 % after 24 months.12 The present study also showed statistically significant association between Inter delivery period < 24 months and Scar dehiscence. This can be attributed to the time needed for proper scar healing.13 Dicle et al, using magnetic resonance imaging, showed that uterine scars needed 6 months at least to reach a normal appearance post-delivery.14

In the present study there was no significant association between Twin gestation and Scar dehiscence. In the present study, there was no significant association between Single layer or double layer closure of uterine incision and scar dehiscence. Roberge et al in their study observed that the operative technique used for closure of the uterine scar, whether single or double layer, had no significant effect on the risk of scar dehiscence.15

In the present study, there was significant association between Pain at caesarean scar and Scar dehiscence. However Suzuki et al observed that there was no association between scar dehiscence and Pain at caesarean scar.16 Scar dehiscence was significantly associated with NICU admissions and Apgar <7 at 5 min. Similar findings were reported by Bashiri et al and this could be attributed to the fact that more premature infants were found to belong to Scar dehiscence group.5

Conclusion

Women with previous caesarean section are at an increased risk for uterine scar dehiscence and rupture. This increases maternal and perinatal morbidity and mortality. In the present study, factors significantly associated with uterine scar dehiscence was preterm delivery < 37 weeks, tertiary caesarean delivery and inter delivery interval < 24 months. Single layer or double layer closure of uterine incision in previous pregnancy was not associated with uterine scar dehiscence. The present study also had increased association between patients with pain at scar site and scar dehiscence. This symptom at the time of admission should be viewed seriously. Increased NICU admission and neonatal Apgar < 7 at 5 min. was associated with scar dehiscence. These factors can be viewed as independent risk factors for scar dehiscence and if not treated in time, can progress to scar rupture.

 

Financial or Other Competing Interests: None.

References

  1. Mussarat N, Qurashi S, Roohi M. Lower segment Caesarean section (LSCS): indications and complications at teahcing hospital, Faisalabad. Professional Med J2013;20(6):916-923.
  2. Ramadan M, Kassem S, Itani S, et al. Incidence and risk factors of uterine scar dehiscence identified at elective repeat Caesarean delivery: a case - control study. J Clin Gynecol Obstet 2018;7(2):37-42.
  3. Cunningham FG, Leveno KH, et al. Prior Caesarean delivery. Williams Obstetrics. 23rd McGraw-Hill Publication 2010: p. 573.
  4. Wang CB, Chiu WWC, Lee CY, et al. Caesarean scar defect: correlation between Caesarean section number, defect size, clinical symptoms and uterine position. Ultrasound Obstet Gynecol 2009;34(1):85-89.
  5. Bashiri A, Burstein E, Rosen S, et al. Clinical significance of uterine scar dehiscence in women with previous Caesarean delivery: prevalence and independent risk factors. J Reprod Med 2008;53(1):8-14.
  6. Thurmond AS, Harvey WJ, Smith SA. Caesarean section scar as a cause of abnormal vaginal bleeding: diagnosis by sonohysterography. J Ultrasound Med 1999;18(1):13-16, quiz 17-18.
  7. Bromley B, Pitcher BL, Klapholz H, et al. Sonographic appearance of uterine scar dehiscence. Int?J?Gynaecol Obstet 1995;51(1):53-56.
  8. Ofili-Yebovi D, Ben-Nagi J, Sawyer E, et al. Deficient lower - segment Caesarean section scars: prevalence and risk factors. Ultrasound Obstet Gynecol 2008;31(1):72-77.
  9. Baron J, Weintraub AY, Eshkoli T, et al. The consequences of previous uterine scar dehiscence and Caesarean delivery on subsequent births. Int?J?Gynaecol Obstet 2014;126(2):120-122.
  10. Armstrong V, Hansen WF, Van Voorhis BJ, et al. Detection of Caesarean scars by transvaginal ultrasound. Obstet Gynecol 2003;101(1):61-65.
  11. Nielsen TF, Ljungblad U, Hagberg H. Rupture and dehiscence of Caesarean section scar during pregnancy and delivery. Am J Obstet & Gynecol 1989;160(3):569-573.
  12. Bujold E, Mehta SH, Bujold C, et al. Interdelivery interval and uterine rupture. Am J Obstet & Gynecol 2002;187(5):1199-1202.
  13. Schwarz OH, Paddock R, Bortnick AR. The Caesarean scar: an experimental study. Am J Obstet & Gynecol 1938;36(6):962-974.
  14. Dicle O, Kucukler C, Pirnar T, et al. Magnetic resonance imaging evaluation of incision healing after Caesarean sections. Eur Radiol 1997;7(1):31-34.
  15. Roberge S, Demers S, Berghella V, et al. Impact of single- vs double - layer closure on adverse outcomes and uterine scar defect: a systematic review and meta-analysis. Am J Obstet & Gynecol 2014;211(5):453-460.
  16. Suzuki S, Sawa R, Yoneyama Y, et al. Preoperative diagnosis of dehiscence of the lower uterine segment in patients with a single previous Caesarean section. Aust?N?Z?J?Obstet Gynaecol 2000;40(4):402-404.

 

Data Sharing Statement

A data sharing statement provided by the authors is available with the full text of this article at jebmh.com

How to cite this article

Anitha N, Deepika K, Prathibha SD. Retrospective study of incidence and risk factors of uterine scar dehiscence identified at repeat Caesarean section. J Evid Based Med Healthc 2020; 7(36), 1976-1979. DOI: 10.18410/jebmh/2020/411