The Best Start - caesarean section rates: review report

Summary

Analysis of current rates and long-term trends of caesarean sections in Scotland, relative to the other two countries in Great Britain and international comparisons where appropriate.

• The overall caesarean section rate in Scotland has risen steadily over the last five decades from 9% in 1975/76 to 35% in 2019/20, the highest rate since records began.
• Caesarean section rates in 2019/20 for England (31%) and Wales (28%) 2019 follow a similar pattern to that seen in Scotland (34.5%) for 2019/20, although Scotland has seen slightly higher rates than the other two nations in recent years.
• Scotland and England have had generally similar trends in the rate of increase in caesarean sections since 1990, with steady increases of 0-1% per year since 1990 and periods of elevated increase from around 1993-2003 and 2013 to present.
• The trend of increasing caesarean section rates has been seen across the world, though to varying extents in different regions and countries. Caesarean section rates tend to be higher in more developed countries. According to data from 150 countries, the proportion of births by caesarean section ranges from 6% to 56% worldwide.
• Mode of delivery differs markedly throughout Europe, with lower levels of caesarean births of around 16% to 17% in most Nordic countries and the Netherlands, and higher caesarean rates in Cyprus, Romania, Bulgaria, Poland, and Hungary of approximately 40% or higher. Other countries with higher than average caesarean rates of around 35% are Italy and Switzerland.
• Differences in cultural and economic context, demographic structure, general healthcare structure and maternal/midwife autonomy in delivery all contribute to the wide range in caesarean section rates seen internationally. However, even in countries for which similarities can be drawn in these respects, there still appears to be wide variation in the caesarean section rate.

A year by year analysis of caesarean section rates by region and description of the variation between health boards

Rates of emergency versus elective caesarean sections – by region, by mothers age, by presentation, previous births, and other factors

• There are wide variations in overall caesarean section rates among health boards in Scotland (from 27% to 42% in 2020).
• The increase in overall caesarean section rates in Scotland is attributable to an increase in both emergency and elective caesarean sections, with both forms of delivery seeing a comparable increase in recent years.
• Mothers from less deprived backgrounds have been more likely to have a caesarean section than those from more deprived backgrounds in recent years and have also accounted for an increasing proportion of all births.
• There has been a gradual increase in the age of mothers giving birth since the 1970s. In 1975/76 the proportion of births to mothers over the age of 35 was 6% compared to 23% in 2020. Older mothers are more likely to have a caesarean section than younger mothers and the proportion of births delivered by caesarean section has increased to a greater extent for older mothers in recent years.
• The proportion of overweight or obese mothers giving birth in Scotland has increased since 2011. In Scotland in 2019/20 over half (53.3%) of pregnant women were overweight or obese. Older mothers are more likely to be recorded as overweight or obese at their antenatal booking and rates of obesity in pregnancy overall are also increasing. Obesity is an independent risk factor for adverse obstetric outcome and is significantly associated with an increased caesarean delivery rate.

Rates of caesarean section alongside maternal mortality/morbidity and stillbirth/neonatal death rates and neonatal morbidity.

• The rate of perinatal deaths and stillbirths in Scotland decreased between 1975/76 and 2019/20, however the rate of this reduction has slowed over time.
• Caesarean section rates of 10-15% are thought to be associated with decreases in maternal, neonatal and infant mortality. When they increase above 10-15%, rates of caesarean section are thought to be no longer associated with lower mortality rates.

The impact of changes to the NICE guidance in 2011 on caesarean section rates^[1]

• The NICE guidelines for caesarean section were revised in 2011 with the main update relating to maternal request for a caesarean section. NICE Guideline CG132 (revised 2011, now NG192) states that women requesting a caesarean with no other indication should be offered appropriate discussion and support, but ultimately, if they are making an informed choice, a caesarean should be offered. The guideline also states that if an obstetrician is unwilling to carry out a caesarean section (CS) the woman should be referred to an obstetrician who will carry out the CS.
• There is some indication from preliminary analysis that experiences across Health Boards in Scotland have varied since the introduction of the update to the NICE guidelines. It is suggested that further exploration of the caesarean section rate at an individual board level is undertaken.
• Recent studies report low rates of caesarean section by maternal request among nulliparous women and many studies have indicated that women are most likely to follow the advice of their obstetrician. However, how embedded a practice, such as caesarean sections has become can influence the advice provided by obstetricians and in turn the rates of delivery by caesarean section.
• The fear of pain associated with labour has been found by many studies to be a contributing factor of caesarean section by maternal request. This is most common among women who have previously had a traumatic birth experience or emergency caesarean section.

Critical analysis of the available literature and evidence on the reasons for caesarean section.

• A combination of higher maternal age, increasing levels of obesity and chronic disease, such as diabetes, mean that more pregnancies are medically complex. This results in higher risk during pregnancy, labour and birth and could be associated with a higher rate of caesarean section.
• The views of obstetricians and midwives, and the role they play in influencing decision making around caesarean sections is important in helping to understand variance in caesarean section rates.
• Literature suggests that a prevalent indication for a primary caesarean section is failure to progress in labour, despite lack of association between relatively prolonged labour without indications of foetal distress and detrimental health outcomes. This coupled with the acceptable time for labour to progress growing progressively shorter over recent decades without any clear medical indication of why, is likely to have had an impact on caesarean section rates.
• Evidence also suggests that once practice has become embedded it is difficult to dislodge. Therefore if caesarean section is an embedded practice this could result in an increase in rates. Factors such as the psychological burden of the threat from clinical negligence and lack of training, skills or experience have been highlighted as barriers to change and to dislodging embedded practices among healthcare professionals.

Evidence-informed actions to address non clinically indicated caesarean sections

• The WHO published guidance focussed on non-clinical interventions for reducing non-clinically indicated caesarean sections, the recommendations are grouped according to the target of the intervention.

• Interventions include educational tools and tailored information for women, introducing a policy of second opinion for caesarean section indications, audits of indications for completed caesarean deliveries using Robson's classification, feedback to those involved in the decision-making process and collaborative working between midwifes and obstetricians.

• Interventions targeted at health organisations or systems may also be effective. Studies have also shown that alternative institutional settings can increase the likelihood of spontaneous vaginal birth, labour and birth without analgesia/ anaesthesia, satisfaction with care, and decrease the likelihood of assisted vaginal birth and caesarean birth. There is a growing body of research which has demonstrated the independent effects of physical attributes of the hospital room on caregivers' behaviour and patients' health outcomes.