Comment
International caesarean section rates: the rising tide Historically, the introduction of caesarean section surgery was associated with an improvement in maternal and perinatal health outcomes. WHO has stated that no empirical evidence exists for an ideal caesarean rate, but “what matters most is that all women who need caesarean sections actually receive them”.1 In areas with very high mortality rates, such as Africa, inadequate availability of caesarean section contributes to substantial maternal and perinatal morbidity and mortality.2 Conversely, in many developed countries, concerns exist about high rates of caesarean section, since increasing rates of this procedure show little evidence of leading to further improvement in perinatal outcomes.3 Caesarean section carries its own risks for maternal and infant morbidity and for subsequent pregnancies.1 At some point, these risks will outweigh the potential benefits associated with lowering the threshold at which the procedure becomes indicated. The skill needed to make a balanced clinical decision for an individual woman might well be greater than the skill required to actually undertake the procedure.4 Joshua Vogel and colleagues’ study in The Lancet Global Health5 provides much-needed data to inform the debate about the global rise in caesarean section rates. Vogel and colleagues analysed data from 287 facilities in 21 countries that were included in both the WHO Global Survey of Maternal and Perinatal Health (2004–08) and the WHO Multi-Country Survey of Maternal and Newborn Health (2010–11). The results show not only the large increase in the caesarean section rate as countries move from lower to higher Human Development Index (HDI) categories, but also that rates are consistently rising even within these categories. As acknowledged by Vogel and colleagues, the data are not necessarily representative of the caesarean section rates in the overall populations of the included countries. The sample populations are drawn from large hospitals (>1000 deliveries per year), almost 70% of which were located urban areas. However, 54% of the world’s population lived in urban areas in 2014, and this percentage is expected to rise to 66% by 2050.6 The study’s results are a signpost for the future of maternity care as country incomes and urbanisation increase, unless changes to birth management can be achieved that will safely reduce the propensity to resort to caesarean delivery. www.thelancet.com/lancetgh Vol 3 May 2015
Vogel and colleagues’ study5 adds depth to the comparison of international caesarean section rates through the use of the Robson classification.7 The Robson classification is a widely accepted, risk-based, ten-group classification system developed specifically to assess caesarean section rates. It allows comparison of clinically meaningful maternity population subgroups and the associated caesarean section rates across institutions, countries, development groups, and time. This system helps to account for some of the population variations that can occur (eg, populations with lower fertility rates will have comparatively more nulliparous births than will more fertile populations). In most countries and HDI categories, the rates of obstetric interventions (both caesarean sections and labour inductions) increased.5 Overall, the caesarean section rate increased over time in all countries except Japan, from 26·4% in the WHO Global Survey to 31·2% in the WHO Multi-Country Survey (p=0·003). Japan’s small decrease in caesarean section rates, including a decline in caesarean section rates for nulliparous women at term in spontaneous or induced labour, was a notable exception and warrants further exploration for lessons to be learnt. The substantial variation in caesarean section rates within HDI categories is also notable, and probably indicates some underuse of appropriate caesarean sections as well as likely overuse of the procedure. This study raises as many questions as it answers. To what extent the caesarean section rate increases are caused by changes in pregnancy management, the availability of maternity services, and patient or provider expectations is not clear. Efforts to explain variation in Australian caesarean section rates within Robson groups showed that patient factors explain most of the variation in prelabour caesarean section rates but not after labour inductions, and that adjustment for private obstetric care, labour, and delivery practices actually increased the amount of unexplained variation in intrapartum caesarean section rates.8 Concerns about high rates of caesarean section in private obstetric care settings also exist in low HDI nations, with countries such as Bangladesh reporting caesarean section rates as high as 73% in private facilities.9 Another important question is whether or not the different rates of caesarean section are associated with variation in
Published Online April 10, 2015 http://dx.doi.org/10.1016/ S2214-109X(15)70111-7 See Articles page e260
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Comment
maternal and infant morbidity. In particular, it would be useful to know whether or not improvements in perinatal mortality have occurred that correspond to each country’s change in caesarean section rate. Ideally, assessment of obstetric interventions and outcomes should be based on high-quality, recent data from the entire population or a representative sample. A key feature of the Robson classification is that it uses information that is available at the onset of labour or delivery, is routinely collected (although this is not necessarily so, even in high-income countries),4 and is reliably reported.7 Data validity is unknown for this study, and the increase over time in maternal records that could not be classified (an indicator of data quality) and the higher than expected relative size of Group 9 (which has been suggested as a self-validation group within the Robson classification)10 is of concern. Vogel and colleagues’ study5 represents an important step in exploring and understanding how obstetric intervention rates are both increasing and also vary widely between countries and levels of development. In the absence of country-specific information about maternal and child health outcomes, caution is needed before recommending strategies aimed at modifying practices. However, this is not to suggest that any efforts to improve the availability of a skilled workforce and health services should be stalled.
CLR is supported by an Australian National Health and Medical Research Council Senior Research Fellowship (#APP1021025). The funder had no role in the preparation, review, or approval of the Comment. We thank Charles Algert for his assistance in preparing and critically reviewing the Comment. We declare no competing interests. Copyright © Roberts et al. Open access article distributed under the terms of CC BY-NC-SA. 1 2
3
4 5
6 7 8
9
10
WHO. Monitoring obstetric care: a handbook. Geneva: WHO Press, World Health Organization, 2009. Chu K, Cortier H, Maldonado F, Mashant T, Ford N, Trelles M. Cesarean section rates and indications in sub-Saharan Africa: a multi-country study from Medecins sans Frontieres. PLoS One 2012; 7: e44484. Ye J, Betrán AP, Guerrero Vela M, Souza JP, Zhang J. Searching for the optimal rate of medically necessary cesarean delivery. Birth 2014; 41: 237–44. Smith GCS. Variation in caesarean section rates in the US: outliers, damned outliers, and statistics. PLoS Med 2014; 11: e1001746. Vogel JP, Betrán AP, Vindevoghel N, et al. Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys. Lancet Glob Health 2015; published online April 10. http://dx.doi.org/10.1016/S2214-109X(15)70094-X. United Nations. World urbanization prospects: 2014 revision. Highlights. New York: United Nations, 2014. Robson MS. Classification of caesarean sections. Fetal and Maternal Medicine Review 2001; 12: 23–39. Nippita T, Lee Y, Patterson J, et al. Variation in hospital caesarean section rates and obstetric outcomes among nulliparae at term: a populationbased cohort study. BJOG 2015; published online Jan 21. DOI:10.1111/1471-0528.13281. Neuman M, Alcock G, Azad K, et al. Prevalence and determinants of caesarean section in private and public health facilities in underserved South Asian communities: cross-sectional analysis of data from Bangladesh, India and Nepal. BMJ Open 2014; 4: e005982. Betrán AP, Vindevoghel N, Souza JP, Gülmezoglu AM, Torloni MR. A systematic review of the Robson classification for caesarean section: what works, doesn’t work and how to improve it. PLoS One 2014; 9: e97769.
*Christine L Roberts, Tanya A Nippita Clinical and Population Perinatal Health Research, The Kolling Institute, University of Sydney, NSW 2065, Australia (CLR, TAN); Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St Leonards, NSW 2065, Australia (TAN) [email protected]
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International caesarean section rates: the rising tide Historically, the introduction of caesarean section surgery was associated with an improvement in maternal and perinatal health outcomes. WHO has stated that no empirical evidence exists for an ideal caesarean rate, but “what matters most is that all women who need caesarean sections actually receive them”.1 In areas with very high mortality rates, such as Africa, inadequate availability of caesarean section contributes to substantial maternal and perinatal morbidity and mortality.2 Conversely, in many developed countries, concerns exist about high rates of caesarean section, since increasing rates of this procedure show little evidence of leading to further improvement in perinatal outcomes.3 Caesarean section carries its own risks for maternal and infant morbidity and for subsequent pregnancies.1 At some point, these risks will outweigh the potential benefits associated with lowering the threshold at which the procedure becomes indicated. The skill needed to make a balanced clinical decision for an individual woman might well be greater than the skill required to actually undertake the procedure.4 Joshua Vogel and colleagues’ study in The Lancet Global Health5 provides much-needed data to inform the debate about the global rise in caesarean section rates. Vogel and colleagues analysed data from 287 facilities in 21 countries that were included in both the WHO Global Survey of Maternal and Perinatal Health (2004–08) and the WHO Multi-Country Survey of Maternal and Newborn Health (2010–11). The results show not only the large increase in the caesarean section rate as countries move from lower to higher Human Development Index (HDI) categories, but also that rates are consistently rising even within these categories. As acknowledged by Vogel and colleagues, the data are not necessarily representative of the caesarean section rates in the overall populations of the included countries. The sample populations are drawn from large hospitals (>1000 deliveries per year), almost 70% of which were located urban areas. However, 54% of the world’s population lived in urban areas in 2014, and this percentage is expected to rise to 66% by 2050.6 The study’s results are a signpost for the future of maternity care as country incomes and urbanisation increase, unless changes to birth management can be achieved that will safely reduce the propensity to resort to caesarean delivery. www.thelancet.com/lancetgh Vol 3 May 2015
Vogel and colleagues’ study5 adds depth to the comparison of international caesarean section rates through the use of the Robson classification.7 The Robson classification is a widely accepted, risk-based, ten-group classification system developed specifically to assess caesarean section rates. It allows comparison of clinically meaningful maternity population subgroups and the associated caesarean section rates across institutions, countries, development groups, and time. This system helps to account for some of the population variations that can occur (eg, populations with lower fertility rates will have comparatively more nulliparous births than will more fertile populations). In most countries and HDI categories, the rates of obstetric interventions (both caesarean sections and labour inductions) increased.5 Overall, the caesarean section rate increased over time in all countries except Japan, from 26·4% in the WHO Global Survey to 31·2% in the WHO Multi-Country Survey (p=0·003). Japan’s small decrease in caesarean section rates, including a decline in caesarean section rates for nulliparous women at term in spontaneous or induced labour, was a notable exception and warrants further exploration for lessons to be learnt. The substantial variation in caesarean section rates within HDI categories is also notable, and probably indicates some underuse of appropriate caesarean sections as well as likely overuse of the procedure. This study raises as many questions as it answers. To what extent the caesarean section rate increases are caused by changes in pregnancy management, the availability of maternity services, and patient or provider expectations is not clear. Efforts to explain variation in Australian caesarean section rates within Robson groups showed that patient factors explain most of the variation in prelabour caesarean section rates but not after labour inductions, and that adjustment for private obstetric care, labour, and delivery practices actually increased the amount of unexplained variation in intrapartum caesarean section rates.8 Concerns about high rates of caesarean section in private obstetric care settings also exist in low HDI nations, with countries such as Bangladesh reporting caesarean section rates as high as 73% in private facilities.9 Another important question is whether or not the different rates of caesarean section are associated with variation in
Published Online April 10, 2015 http://dx.doi.org/10.1016/ S2214-109X(15)70111-7 See Articles page e260
e241
Comment
maternal and infant morbidity. In particular, it would be useful to know whether or not improvements in perinatal mortality have occurred that correspond to each country’s change in caesarean section rate. Ideally, assessment of obstetric interventions and outcomes should be based on high-quality, recent data from the entire population or a representative sample. A key feature of the Robson classification is that it uses information that is available at the onset of labour or delivery, is routinely collected (although this is not necessarily so, even in high-income countries),4 and is reliably reported.7 Data validity is unknown for this study, and the increase over time in maternal records that could not be classified (an indicator of data quality) and the higher than expected relative size of Group 9 (which has been suggested as a self-validation group within the Robson classification)10 is of concern. Vogel and colleagues’ study5 represents an important step in exploring and understanding how obstetric intervention rates are both increasing and also vary widely between countries and levels of development. In the absence of country-specific information about maternal and child health outcomes, caution is needed before recommending strategies aimed at modifying practices. However, this is not to suggest that any efforts to improve the availability of a skilled workforce and health services should be stalled.
CLR is supported by an Australian National Health and Medical Research Council Senior Research Fellowship (#APP1021025). The funder had no role in the preparation, review, or approval of the Comment. We thank Charles Algert for his assistance in preparing and critically reviewing the Comment. We declare no competing interests. Copyright © Roberts et al. Open access article distributed under the terms of CC BY-NC-SA. 1 2
3
4 5
6 7 8
9
10
WHO. Monitoring obstetric care: a handbook. Geneva: WHO Press, World Health Organization, 2009. Chu K, Cortier H, Maldonado F, Mashant T, Ford N, Trelles M. Cesarean section rates and indications in sub-Saharan Africa: a multi-country study from Medecins sans Frontieres. PLoS One 2012; 7: e44484. Ye J, Betrán AP, Guerrero Vela M, Souza JP, Zhang J. Searching for the optimal rate of medically necessary cesarean delivery. Birth 2014; 41: 237–44. Smith GCS. Variation in caesarean section rates in the US: outliers, damned outliers, and statistics. PLoS Med 2014; 11: e1001746. Vogel JP, Betrán AP, Vindevoghel N, et al. Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys. Lancet Glob Health 2015; published online April 10. http://dx.doi.org/10.1016/S2214-109X(15)70094-X. United Nations. World urbanization prospects: 2014 revision. Highlights. New York: United Nations, 2014. Robson MS. Classification of caesarean sections. Fetal and Maternal Medicine Review 2001; 12: 23–39. Nippita T, Lee Y, Patterson J, et al. Variation in hospital caesarean section rates and obstetric outcomes among nulliparae at term: a populationbased cohort study. BJOG 2015; published online Jan 21. DOI:10.1111/1471-0528.13281. Neuman M, Alcock G, Azad K, et al. Prevalence and determinants of caesarean section in private and public health facilities in underserved South Asian communities: cross-sectional analysis of data from Bangladesh, India and Nepal. BMJ Open 2014; 4: e005982. Betrán AP, Vindevoghel N, Souza JP, Gülmezoglu AM, Torloni MR. A systematic review of the Robson classification for caesarean section: what works, doesn’t work and how to improve it. PLoS One 2014; 9: e97769.
*Christine L Roberts, Tanya A Nippita Clinical and Population Perinatal Health Research, The Kolling Institute, University of Sydney, NSW 2065, Australia (CLR, TAN); Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St Leonards, NSW 2065, Australia (TAN) [email protected]
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