Impact Factor 1.022
Volume 33, 12 Issues, 2023
  Clinical Practice Article     January 2023  

An Evaluation of Cesarean Delivery Rates According to Robson Classification in the Black Sea Region of Turkey

By Seda Keskin1, Deha Denizhan Keskin1, Sedat Bostan2

Affiliations

  1. Department of Obstetrics and Gynecology, Faculty of Medicine, Ordu University, Ordu, Turkey
  2. Department of Health Management, Faculty of Health Sciences, Ordu University, Ordu, Turkey
doi: 10.29271/jcpsp.2023.01.92

ABSTRACT
Objective: To analyse cesarean deliveries (CD) using the Ten Group Classification System (TGCS) for reducing cesarean rates.
Study Design: Cross-sectional study.
Place and Duration of Study: Ordu University Medical Faculty Training and Research Hospital, Ordu, Turkey, from 1st January 2008 to 31st December 2020.
Methodology: A total of 29,885 deliveries during the 13-year study period were analysed. Group sizes and annual, overall, absolute, and relative CD rates were calculated to analyse the effect of the Robson groups (RGs)/TGCS. The data were analysed using the two-way Chi-square test and two-proportion Z-test with Bonferroni correction.
Results: The overall CD rate was 59.22% (17,697). The principal contributors to the overall CD rate were RG5 (54.48%), RG1 (12.52%), and RG2 (10.06%). The relative CD rate in preterm pregnancies (RG10) increased approximately five-fold over the 13-year study period due to the increase in both group size and absolute CD rate (p<0.001).
Conclusion: TGCS shows the cesarean delivery trends in terms of cesarean rates and identifies those groups requiring special precautions. The target groups (RG5, RG1, RG2 and RG10) need more in-depth research to reduce CD rates. Various approaches need to be implemented including individualised cesarean indication, encouragement of vaginal delivery after cesarean delivery, expectant management in nulliparous women, and spontaneous labor for preterms labor.

Key Words: Cesarean section, Elective cesarean section, Induction of labor, Vaginal birth after cesarean section, Robson classification, Preterm deliveries.

INTRODUCTION

Cesarean delivery (CD) is a life-saving surgery when performed with indications such as dystocia, uterine rupture, and placenta previa. However, overuse has potentially adverse effects on both mother and newborn health.1 In particular, there is growing concern regarding maternal complications in the long term. Individualising cesarean indications and determining optimised CD rates are therefore highly important for public health.2

The fear of labor pain and concerns about complications related to vaginal delivery are the most common causes of rising cesarean rates.3 Malpractice pressure is the principal reason why obstetricians prefer to avoid vaginal delivery. Factors such as an excessive delivery load in the hospital, a shortage of nurses/midwives, lack of training in vaginal delivery, and insufficient patient-doctor relationships may also lead to a preference for CD.4

The World Health Organisation (WHO) describes an acceptable CD rate as between 10% and 15%. Turkey has the fourth highest CD rate in the world, at 53.1%, a figure exceeded only by the Dominican Republic, Brazil, and Egypt.In 2015, the WHO adopted the Ten Group Classification System (TGCS) as a global standard for evaluating, analysing, and optimising CD rates.5,6 RG1 is defined as nulliparous/singleton/cephalic/term/spontaneous labor; RG2 as nulliparous/singleton/cephalic/term/induced labor or cesarean section before labor; RG3 as multiparous without previous cesarean section/singleton/cephalic/term/spontaneous labor; RG4 as multiparous without previous cesarean section/singleton/cephalic/term/induced labor or caesarean section before labor; RG5 as multiparous with prior cesarean section/singleton/cephalic/term; RG6 as all nulliparous breeches; RG7 as all multiparous breeches; RG8 as all multiple pregnancies; RG9 as all pregnancies with transverse/oblique lie; RG10 as singleton/cephalic/preterm.6

The main goal of this study was to evaluate the reasons and pace of change in the causes of cesarean section over the years, and to provide a data source for Health Authorities to consider while providing institutional arrangements and preventive health services.
 

METHODOLOGY

This cross-sectional study was conducted at Ordu University Medical Faculty Training and Research Hospital. The research commenced following the receipt of approval from the Ordu University Medical Faculty Clinical Research Ethics Committee (no: KAEK-2021/59). All women who delivered at the hospital from 1st January, 2008 to 31st December 2020, were grouped under the TGCS and included in the analysis.

The variables collected for TGCS included obstetric characteristics such as gestational age at delivery, parity, fetal presentation, number of fetuses, presence of uterine scar, and the onset of labor. Inclusion criteria were defined as all births in 13 year period. Women giving birth during the study period to live newborns after at least 24 weeks’ gestation and/or with a birth weight of at least 500 grams (g) were included in the study. Birth weight below 2500 g was regarded as preterm (>37 weeks). Exclusion criteria were patients for whom complete file data could not be obtained. The total number of women in each group and group sizes and CD rates are shown in Tables 1-3. Three groupings by years (2008-2010/2013-2015/2018-2020) were established in order to reveal the chronological changes in cesarean trends.

Two-way Chi-square test was used to determine whether the group sizes in Robson groups changed in a time-dependent manner. Two-proportion Z-test with Bonferroni correction was applied to compare absolute CD rates between two periods. All statistical analyses were performed on SPSS v26 (IBM Inc., Chicago/IL/USA) statistical software. A p-value (two-sided) less than 0.05 was regarded as statistically significant.

RESULTS

A total of 29,885 women gave birth at our hospital during the 13-year study period. RG5 was identified as the largest group (32.47%). Nulliparous and multiparous women with spontaneous labor represented 21.64% and 19.87% of the study population, respectively. The labor induction rate was 16.34%. Preterm cephalic singletons represented 5.51% of all deliveries. The malpresentation rate was 3.1%. Three hundred twenty-one women (1.07%) had multiple pregnancies.

An increase in the number of deliveries was observed in RG5 (p<0.001) and RG10 (p<0.001) from 2008 to 2020, together with a decrease in RG2 (p=0.000) and RG4 (p<0.001), especially after 2011. A horizontal course was determined in the other Robson groups. At group size comparisons, RG1 was 2.45-fold larger than RG2 overall (1.47:1/6.90:1), and RG3 was 2.63-fold larger than RG4 overall (1.56:1/8.32:1). In other words, spontaneous initiation of labor was preferred over the induction of labor or elective cesarean delivery in nulliparous and multiparous women. On the one hand, the increased group sizes in RG5 and RG10 caused a significant increase in the relative CD rates due to the already high absolute CD rate (p=0.000). However, on the other hand, the decreasing group sizes and absolute CD rates in RG2 and RG4 caused a significant decrease in the relative CD rate (p<0.001).

The overall CD rate was 59.22% (17,697). The lowest CD rate over the 13-year study period was in 2012, at 52.42%, while the highest was in 2010, at 65.93%. The absolute CD rates in each group ranged from 13.92% in RG3 up to 100% in RG9. Absolute CD rates decreased significantly over the years in RG1 (p=0.000), RG2, RG3, and RG4 (all p<0.001), while a statistically significant increase was observed in RG10 (p<0.001). RG5 was the greatest relative contributor to the overall CD rate, at 54.48%, followed by RG1, RG2, RG4, RG10, and RG3. In terms of the relative contribution of the group to overall CD rates by years, relative CD rates decreased significantly in RG1, RG2, and RG3, and RG4 (all p<0.001), while statistically significant increases were observed in RG5 (p<0.001) and RG10 (p<0.001).

DISCUSSION

The CD rate is one of the best indicators of the quality of a health system.7 Previous studies have shown that an optimal CD rate reduces maternal and neonatal mortality.4 The overall CD rate in the present study was 59.22%, compared to 53.1% in Turkey as a whole. The CD rate at the study centre was even higher than that in the Dominican Republic (58.1%), the country with the highest global CD rates.1

Traditional classification systems using common cesarean indications are not by themselves capable of explaining the leading factors contributing to high CD rates. Although it is not commonly employed in Turkey, many countries report controlling CD rates using the TGCS. This system can be employed to develop health policies and preventive strategies for specific groups with greater impacts on CD rates.5

An annual decrease in birth numbers was observed in the present study. Although there was a slight decrease in CD rates until 2016, these then increased rapidly and today exceed 60%. This widespread overuse of CD is an important issue because of the potential maternal and perinatal risks that increase healthcare costs and exacerbate inequality in access to maternity healthcare.8 RG5, RG1, and RG2 were the main drivers of the overall CD rate in the hospital. Since the number of CDs in these three groups constituted 77.06% of overall CD, these were identified as our target groups.

Similarly to other studies, multiparous women in RG5 were an increasingly important determinant of overall CD rates.9 The absolute group CD rate was 99.36%, meaning that the management of women from RG5 in this hospital involved cesarean section (CS) being scheduled without any trial of labor.

Previous studies have reported a 70% success rate for vaginal birth after the previous cesarean section (VBAC). This high rate suggests that VBAC can be offered as a cost-effective option for multiparous women with one previous uterine scar.10 The common culture of “once a CS, always a CS” among the population played a major role in the rejection of the VBAC option. As described in other studies, this global impact is observed in many countries.11

Table I: Distribution of the study population according to the TGCS system.

Robson Group

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

Total

1

n

807

673

556

414

490

409

461

611

529

419

321

431

346

6467

%

21.20

19.70

20.11

21.54

21.21

21.50

21.94

22.88

27.68

23.82

18.57

21.91

21.29

21.64

2

n

548

432

341

208

213

157

162

175

113

78

66

86

50

2629

%

14.40

12.64

12.33

10.82

9.22

8.25

7.71

6.55

5.91

4.43

3.82

4.37

3.08

8.80

3

n

757

665

513

327

449

362

448

595

414

393

286

397

333

5939

%

19.89

19.46

18.55

17.01

19.44

19.03

21.32

22.28

21.66

22.34

16.54

20.18

20.49

19.87

4

n

485

396

314

157

172

137

146

146

78

66

52

63

40

2252

%

12.74

11.59

11.36

8.17

7.45

7.20

6.95

5.47

4.08

3.75

3.01

3.20

2.46

7.54

5

n

857

932

822

636

781

656

689

891

614

628

806

757

635

9704

%

22.52

27.28

29.73

33.09

33.81

34.49

32.79

33.36

32.13

35.70

46.62

38.49

39.08

32.47

6

n

114

91

55

36

43

40

35

51

33

32

20

46

37

639

%

3.00

2.66

1.99

1.87

1.86

2.10

1.67

1.91

1.73

1.82

1.16

2.34

2.28

2.14

7

n

33

42

23

15

25

14

19

22

16

9

13

13

12

250

%

0.87

1.23

0.83

0.78

1.08

0.74

0.90

0.82

0.84

0.51

0.75

0.66

0.74

0.84

8

n

62

48

25

17

19

15

16

21

23

14

20

17

24

321

%

1.63

1.40

0.90

0.88

0.82

0.79

0.76

0.79

1.20

0.80

1.16

0.86

1.48

1.07

9

n

6

5

4

2

3

2

3

3

2

1

1

2

2

36

%

0.16

0.15

0.14

0.10

0.13

0.11

0.14

0.11

0.10

0.06

0.06

0.10

0.12

0.12

10

n

137

133

112

110

115

110

122

156

89

119

144

155

146

1648

%

3.60

3.89

4.05

5.72

4.98

5.78

5.81

5.84

4.66

6.77

8.33

7.88

8.98

5.51

Total delivery

3806

3417

2765

1922

2310

1902

2101

2671

1911

1759

1729

1967

1625

29885

CD rate (%)

64.98

65.53

65.93

54.79

52.42

55.89

55.31

52.71

49.61

55.20

62.98

62.79

62.89

59.22

n:  Number of all deliveries (vaginal delivery and cesarean delivery) in each group;  %: Group size (%) = number of women in the group / number of total deliveries;  CD rate (%): Cesarean delivery rate (%) = number of cesarean deliveries / number of total deliveries.


Table II: Distribution of cesarean deliveries according to the TGCS system.

Robson Group

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

p*

Total

1

n

369

309

265

118

131

126

149

159

126

122

76

146

119

 

2215

Absolute CD rate (%)

45.72a

45.91a

47.66a

28.50bc

26.73bc

30.81bc

32.32bc

26.02bc

23.82c

29.12bc

23.68bc

33.87b

34.39b

0.000

34.25

Relative CD rate (%)

14.92

13.80

14.54

11.21

10.82

11.85

12.82

11.29

13.29

12.56

6.98

11.82

11.64

0.862

12.52

2

n

478

363

272

109

100

86

93

83

39

42

24

57

35

 

1781

Absolute CD rate (%)

87.23a

84.03a

79.77a

52.40bc

46.95bc

54.78bc

57.41bc

47.43bc

34.51c

53.85bc

36.36c

66.28b

70.00b

0.000

67.74

Relative CD rate (%)

19.33

16.21

14.92

10.35

8.26

8.09

8.00

5.89

4.11

4.33

2.20

4.62

3.42

0.000

10.06

3

n

175

151

131

27

27

34

43

49

33

35

21

55

46

 

827

Absolute CD rate (%)

23.12a

22.71a

25.54a

8.26b

6.01c

9.39bc

9.60bc

8.24bc

7.97bc

8.91bc

7.34bc

13.85b

13.81b

0.000

13.92

Relative CD rate (%)

7.08

6.74

7.19

2.56

2.23

3.20

3.70

3.48

3.48

3.60

1.93

4.45

4.50

0.953

4.67

4

n

339

258

193

52

48

48

56

48

24

24

9

33

22

 

1154

Absolute CD rate (%)

69.90a

65.15a

61.46a

33.12bc

27.91c

35.04bc

38.36bc

32.88bc

30.77bc

36.36bc

17.31c

52.38ab

55.00ab

0.000

51.24

Relative CD rate (%)

13.71

11.52

10.59

4.94

3.96

4.52

4.82

3.41

2.53

2.47

0.83

2.67

2.15

0.051

6.52

5

n

852

927

817

631

776

651

684

886

609

626

801

752

630

 

9642

Absolute CD rate (%)

99.42

99.46

99.39

99.21

99.36

99.24

99.27

99.44

99.19

99.68

99.38

99.34

99.21

0,999

99.36

Relative CD rate (%)

34.45c

41.40c

44.82c

59.92b

64.08b

61.24b

58.86b

62.93b

64.24b

64.47b

73.55a

60.89b

61.64b

0.000

54.48

6

n

112

90

54

36

42

40

34

50

33

31

20

46

37

 

625

Absolute CD rate (%)

98.25

98.90

98.18

100

97.67

100

97.14

98.04

100

96.88

100

100

100

0.948

97.81

Relative CD rate (%)

4.53

4.02

2.96

3.42

3.47

3.76

2.93

3.55

3.48

3.19

1.84

3.72

3.62

0.999

3.53

7

n

29

37

19

14

22

12

17

20

15

9

13

13

12

 

232

Absolute CD rate (%)

87.88

88.10

82.61

93.33

88.00

85.71

89.47

90.91

93.75

100

100

100

100

0.773

92.80

Relative CD rate (%)

1.17

1.65

1.04

1.33

1.82

1.13

1.46

1.42

1.58

0.93

1.19

1.05

1.17

0.947

1.31

8

n

60

46

23

16

18

14

16

20

22

13

20

17

24

 

309

Absolute CD rate (%)

96.77

95.83

92.00

94.12

94.74

93.33

100

95.24

95.65

92.86

100

100

100

0.937

96.26

Relative CD rate (%)

2.43

2.05

1.26

1.52

1.49

1.32

1.38

1.42

2.32

1.34

1.84

1.38

2.35

0.927

1.75

9

n

6

5

4

2

3

2

3

3

2

1

1

2

2

-

36

Absolute CD rate (%)

100

100

100

100

100

100

100

100

100

100

100

100

100

-

100

Relative CD rate (%)

0.24

0.22

0.22

0.19

0.25

0.19

0.26

0.21

0.21

0.10

0.09

0.16

0.20

-

0.20

10

n

53

53

45

48

44

50

67

90

45

68

104

114

95

 

876

Absolute CD rate (%)

38.69c

39.85c

40.18c

43.64c

38.26c

45.45bc

54.92bc

57.69bc

50.56c

57.14c

72.22a

73.55a

65.07ab

0.000

53.16

Relative CD rate (%)

2.14

2.37

2.47

4.56

3.63

4.70

5.77

6.39

4.75

7.00

9.55

9.23

9.30

0.463

4.95

n: Number of CD in each group = number of all cesarean deliveries in each group; Absolute CD rate (%): Absolute group CD rate (%) = number of cesarean deliveries in the group / number of all deliveries in the group; Relative CD rate (%): Relative contribution of the group to the overall CD rate (%) = number of cesarean sections in the group / number of total cesarean deliveries; -: Not calculated; *:Chi-square test; a,b,c: The difference between rates for years that do not share a common letter is statistically significant (p<0.05)

While encouraging the patient to deal with VBAC, it should also be emphasised that repeated CS can lead to abnormal placentation and subfertility. In addition, repeated CS results in adverse effects on national economies. The impact is greater in underdeveloped countries with high fertility rates and limited resources with which to perform basic obstetric interventions.12

Measures should be taken to reduce the CD rates in RG5. In the first stage, it may be beneficial to establish dedicated VBAC clinics in hospitals. These specialised clinics can select women with a high probability of delivery by the vaginal route among members of this group. In addition, research has revealed that most obstetricians discourage VBAC due to their busy schedules. Educating midwives working in the VBAC clinic will also reduce the clinician workload, one of the causes of increased CD rates in this group.13

Nulliparous population in RG1 and RG2 was the most frequent contributor to the overall CD rate in the present study, after RG5. The adverse consequences of the increases in these groups on women’s health have been shown in previous studies.14,15A higher CD rate was observed in RG2 compared to RG1 in the present study due to labor induction (67.74/34.25, respectively). In addition, the CD rates in both groups (RG1 and RG2) fluctuated over the years. Despite the high rates of CS, the contribution to the relative CD rate of RG2 decreased in line with the sharp decrease in the group size.

Table III: Changes in group size, and absolute and relative CD rates by years (2008-2010/2011-2012/2013-2015/2016-2017/2018-2020).

Robson Group

2008-2010

2013-2015

2018-2020

p*

1

Group Size (%)

20.38b

22.19a

20.64ab

0.015

Absolute CD rate (%)

46.32a

29.30b

31.06b

0.000

Relative CD rate (%)

14.43a

11.95b

10.19b

0.000

2

Group Size (%)

13.23a

7.40bc

3.80c

0.000

Absolute CD rate (%)

84.25a

53.04b

57.43b

0.000

Relative CD rate (%)

17.03a

7.21b

3.47c

0.000

3

Group Size (%)

19.37b

21.05a

19.09b

0.009

Absolute CD rate (%)

23.62a

8.97c

12.01b

0.000

Relative CD rate (%)

6.99a

3.47b

3.47b

0.000

4

Group Size (%)

11.96a

6.43b

2.91c

0.000

Absolute CD rate (%)

66.11a

35.43b

41.29b

0.000

Relative CD rate (%)

12.09a

4.18b

1.91c

0.000

5

Group Size (%)

26.14c

33.50b

41.30a

0.000

Absolute CD rate (%)

99.43

99.33

99.32

0.873

Relative CD rate (%)

39.72b

61.13a

65.24a

0.000

6

Group Size (%)

2.60b

1.89b

1.94b

0.002

Absolute CD rate (%)

98.46

98.41

100.00

0.444

Relative CD rate (%)

3.92

3.41

3.08

0.087

7

Group Size (%)

0.98

0.82

0.71

0.213

Absolute CD rate (%)

86.73

89.09

100.00

0.065

Relative CD rate (%)

1.30

1.35

1.14

0.702

8

Group Size (%)

1.35b

0.78b

1.15ab

0.003

Absolute CD rate (%)

95.56

96.15

100.00

0.254

Relative CD rate (%)

1.97

1.38

1.82

0.089

9

Group Size (%)

0.15

0.12

0.09

0.636

Absolute CD rate (%)

100.00

100.00

100.00

-

Relative CD rate (%)

0.23

0.22

0.15

0.695

10

Group Size (%)

3.82c

5.81b

8.36a

0.000

Absolute CD rate (%)

39.53c

53.35b

70.34a

0.000

Relative CD rate (%)

2.31c

5.70b

9.35a

0.000

Total delivery

9988

6674

5321

 

CD rate (%)

65.43

54.44

62.88

 

Group size (%) = number of women in the group / number of total deliveries. Absolute CD rate (%): Absolute group CD rate (%) = number of cesarean deliveries in the group / number of all deliveries in the group. Relative CD rate (%): Relative contribution of the group to the overall CD rate (%) = number of cesarean sections in the group / number of total cesarean deliveries. CD rate (%): Cesarean delivery rate (%) = number of cesarean deliveries / number of total deliveries. -: Not calculated; *:Chi-square test; a,b,c: The difference between rates of years that do not share a common letter is statistically significant (p<0.05).

Consistent with the present study, previous research has emphasised the importance of RG1, and especially RG2.16As reported in a number of studies, a group size ratio between RG1 and RG2 below 2:1 indicates excessive application of labor induction. Stricter indications for the induction of labor in this group should therefore be formulated in clinics, and oxytocin must be used if essential.17 This ratio increased gradually from 1.47 in 2008 to 6.91 in 2020. In other words, labor induction is less applied in case of nulliparous women in the clinic. This ratio should therefore be constantly monitored and kept high since a low ratio is directly related to a high primary CD rate.

The relative CD rate in RG10 increased approximately five-fold over the 13-year study period. It may be attributed to the study centre being a tertiary case university Hospital that provides neonatal intensive care services. On the other hand, induction of labor and elective CS, which the authors use for high-risk pregnancies, increase the odds of iatrogenic prematurity. Similar results have been reported in studies from institutions providing tertiary health services.18 The perception that 'CS is protective' in preterms may be therefore inaccurate in some instances.

Similarly to previous studies, birth weight was also used instead of pregnancy estimation confirmed by first-trimester ultrasonography in preterm diagnosis in the present research. However, using birth weight in preterm diagnosis may result in growth-restricted neonates being misclassified as preterm. This may then result in a relative increase in the size of RG10.19 There is no definite choice of delivery method that is internationally accepted and applied to the overall RG10 population in preterm pregnancies. A Cochrane review concluded that there was no difference between caesarean and vaginal delivery groups in terms of neonatal asphyxia, low Apgar score, hypoxic-ischemic encephalopathy, or respiratory distress syndrome. However, the presence of one or more of the additional CS indications encourages obstetricians to decide in favor of CD.20

In addition, an examination of RG10 on a yearly basis revealed that the absolute CD rates increased rapidly, from 40% in 2008 to 65-73% in the last three years. Additional CS indications should therefore be examined objectively, and labor induction should be applied with limited indications in order to reduce the high CD rates in RG10.

CONCLUSION

This study used the TGCS to identify specific groups with the greatest contribution to overall CD over a 13-year period. RG5 emerged as the leading contributor to the overall CD rates, followed by RG1 and RG2. In addition, the contribution of preterm pregnancies (RG10) to the increasing CD rates increased considerably in a time-dependent manner. Measures that might be usefully adopted include encouraging VBAC, determining labor induction protocols in the nulliparous population in particular, and clarifying CS indications in preterm pregnant women.

FUNDING:
No company or institution has financially contributed to the study.

ACKNOWLEDGEMENT:
The authors are indebted to Assistant Professor Yeliz Kasko Arici, head of the Ordu University Faculty of Medicine, Department of Biostatistics and Medical Informatics, who contributed greatly to the statistical analysis.

ETHICAL APPROVAL:
Ethical approval of this study was obtained from the Clinical Research Ethics Committee of Ordu University Medical Faculty (Date: 04/03/2021, No. KAEK-2021/59), prior to initiation of the research work.                                    

COMPETING INTEREST:
The authors declared no competing interest.

AUTHORS’ CONTRIBUTION:
SK: Writing original draft, the conception of the work, methodology, analysis, and interpretation of the data for the work.
DDK: Investigation, data curation, supervision, writing review, and editing.
SB: Formal analysis, methodology, supervision, and resources.
All the authors have critically reviewed the final version of the manuscript and approved it for publication.

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