Caesarean Section: Controversies, Audit, Classification and Indications

Controversies

The caesarean section (CS) debate continues to be amongst the most controversial issues in obstetrics and gynaecology, possibly in medicine. The debate has focused on what the appropriate CS rate should be against a background of increasing CS rates worldwide, albeit increasing at different rates and having begun at different starting points. Although much has been written, it is difficult to conclude that any consensus or anything of clinical value has been achieved. All professionals involved in labour and delivery must take responsibility for this failure and for the mixed messages being given, which leave women uncertain about what is best for them and their babies. A reassessment of our care in labour and delivery needs to take place, where safety and quality is at the centre of the debate.

CS for maternal request deserves a special comment. Current international clinical guidelines now reflect a liberalization of expert opinion on CS, often leaving the responsibility, and therefore the accountability, on the woman’s shoulders, which is a radical shift from the paternalistic type of medical care provided in the past. The UK National Institute for Health and Care Excellence (NICE) guidelines recommend that elective CS on maternal request should be facilitated after full consent is obtained. The American College of Obstetricians and Gynecologists and Australia and New Zealand’s RANZCOG also advocate discussion of and patient input into delivery model.

However, a concerning aspect of these guidelines is that there has been no attempt to define maternal request nor has any standard classification of CS been recommended, despite a systematic review on the merits of different classification systems.

An internationally accepted classification is much needed to enable study of the effects of rising CS rates. This requires endorsement both at international and national levels, making it part of mandatory reporting by each labour and delivery unit. Indeed it is the responsibility of professionals to make this happen. In the future, the failure to study the rising CS rate scientifically rather than the increase in the CS rate itself will be most critically questioned.

Caesarean Section Audit

Can we reduce the caesarean section rate? Yes, but only when it can be justified, accepted by women and safely implemented. M Robson

Audit of CS rates always starts with the total CS rate as a percentage of total deliveries, normally taken as all deliveries above 500 g or 24 weeks’ gestation.

The next step divides CSs into prelabour and spontaneous or induced labour. This is an important step as the classification of indications will be different for the two groups. It is important to note that induced labour includes all women once they have been started on the process of induction, even if they do not actually go into labour, as it is based on the intention to treat principle. This is an important aspect of the analysis of all labour and delivery audit.

The commonly used terms elective and emergency CS are difficult to define and are rarely applied in a standard way. There is a need for more objective and consistent methodology, whatever the different views are. Providing the information is collected consistently; clinicians can then use the information in the way they want.

An elective CS might best be defined as a planned procedure (>24 hours before), carried out during routine working hours, at greater than 39 weeks’ gestation, in a woman who is neither in spontaneous labour nor has had the labour induction process started. All other CS should be audited as emergency or, possibly more appropriately, as nonelective CS. The reasons why they were recorded as nonelective could be recorded using the rationale described above, for example, whether a CS was out of routine hours using emergency staff or was not a planned procedure. This adds organizational and resource elements, as well as clinical, to the definition of elective and nonelective (emergency) surgery, and would be helpful in assessing a CS rate. The definition of gestation does not necessarily have to be part of the primary definition of elective or nonelective, but some may find it useful.

The importance of using the methodology described above is that immediately conclusions can be drawn on whether a certain CS rate relates to issues prior to or during labour and after induction, as a proportion of the overall CS rate. It is important to understand this before studying in detail any other aspect of CS rates. The importance of indications in relation to this classification will be discussed in more detail later on.

Ten Group Classification System

The Ten Group Classification System (TGCS) was first published in 2001 and the standard method of presentation of CS data is shown in Table 24.1 . There are a number of publications in the literature describing both how to use it and also how it has been used in different delivery units. However, the best summary of its use is found in the WHO manual.

The TGCS has been used extensively internationally to analyse CS deliveries, but it was originally designed so that all labour and delivery events and outcomes could be analysed in the context of the different types of management that each unit may have. In addition, significant epidemiological variables could be incorporated either within the 10 groups or used to analyse the distribution of the 10 groups within different epidemiological subgroups (see Chapter 43 ).

The way the TGCS table is constructed and presented is important ( Table 24.1 ). It is essential that there is a disciplined and standard way of interpreting the results. Any particular group can only be interpreted individually in detail after first interpreting the different relative sizes of the other nine groups. The reason for this is just to confirm the overall data quality.

The groups are described and numbered in the first two columns, shown in Table 24.1 . Ten groups were chosen to give some discrimination to the population; more than 10 would become difficult to remember. The different groups were chosen because of their clinical relevance and some were chosen to assist the determination of data quality. The order and relationships of the groups in the table are also important, to enable rapid and easy interpretation of the data. All groups can be subdivided and some groups need to be amalgamated to provide more appropriate denominators, depending on the events and outcomes being analysed. However, experience of using the TGCS nationally and internationally to compare data confirms that it is important to start with the standard table and to ensure that there is a disciplined approach to this. The 10 groups become a common starting point for further analysis.

The third column heading in Table 24.1 provides the numerator for the total number of CS deliveries and the denominator for the total number of women who delivered in the institution; the column contains the numerator and denominator for the number of CS deliveries and women who delivered, respectively, for each group. The numbers in each group should add up to the totals at the top. The number and percentage of women that cannot be classified should be recorded as an addendum to the table and gives a reflection of data quality.

The fourth column in the table ( Table 24.1 ) gives the size of each group as a percentage, which is calculated by the number of women in each group divided by the total number of women in the population. It is remarkable how consistent the sizes are in different populations and it therefore becomes relatively easy to either question the quality of the data or indeed identify unique populations. The relative sizes of the groups must always be carefully assessed before looking at the CS rates in the individual groups.

The fifth column in the table provides the CS delivery rate in each group by dividing the number of CS carried out in each group by the number of women in each group.

The sixth column provides the absolute contribution of each group to the overall CS delivery rate. This is calculated by dividing the number of CS deliveries in each group by the total number of women in the population. The contribution to the overall CS delivery rate is influenced by the CS delivery rate in each group and also the size of the group. The absolute (rather than relative) rate of contribution is recommended for use, as shown in Table 24.1 . It is then easy to quickly interpret both the absolute and relative rates of contribution to the CS delivery rate.

By using the TGCS, the size of the groups and the CS rate within the groups immediately gives significant information about the type of care being provided in that institution, region or country. When other epidemiological information, events and outcomes, processes or cost are then analysed within the different groups, as opposed to a proportion of the total population, they also increase in relevance. Finally then the risk/benefit ratio of CS rates within the groups takes on a totally different significance and CS rates therefore qualify as a marker of quality care, especially when interpreted in relation to this other information.