Infection concerns over Caesarean rise

Speaking at Ethicon’s annual symposium on surgical site infection, Claire Banks, senior specialist registrar in obstetrics and gynaecology, West of Scotland Deanery, NHS Education for Scotland, pointed out that the rate of Caesarean sections (CS) in the UK has increased from just 9%, in 1980, to around 25% in recent years – the equivalent of 155,000 births per year. Of these CS births, 62,000 are elective procedures. However, the percentage varies throughout the UK, with some private units recording rates as high as 35%. This pales into insignificance compared to worldwide figures, however. In China the figure is 46% – while, in some parts of Brazil, the figure reaches almost 80%. This is despite the fact that the World Health Organization recommends that the rate should not be more than 10% to 15% – i.e. the same rate as 30 years ago. Several factors could be responsible for this rise, including a general increase in levels of obesity. A referral to an anaesthetist was previously made for a BMI of over 30, at booking, but as obesity has become more common, women are now only referred if they have a BMI greater than 40. Obesity is also associated with several other risks in pregnancy, including the development of conditions such as gestational diabetes, hypertension and pre-eclampsia. This may mean an increase in the rates of induction of labour, which in turn leads to failed induction or failure to progress in labour, and these are two significant reasons given for performing a CS.

A mother’s larger size can sometimes lead to a larger baby, but it may also result in growth restriction (although these babies are also common in women of lower socioeconomic class or smokers). Claire Banks explained that these babies do not tend to tolerate labour as well, leading to another main reason for CS (i.e. fetal distress). Other influential factors include increasing maternal age, increased use of IVF and teenage pregnancies. “Increasing maternal age and IVF pregnancies are not necessarily a problem, but among this group are women from the ‘maternal request’ category. There is also an increased incidence of multiple births with IVF. Unfortunately, a significant number of our patients are also in the teenage category i.e. the 14-16 age group. Although they usually want to avoid CS, sometimes their pelvis is just too ‘immature’ to allow passage of the baby. “Finally, repeat CS accounts for up to a quarter of all CS procedures performed, and is perhaps the only variable that we may be able to do something about – by encouraging women to have a trial of vaginal delivery following previous CS.” Claire Banks pointed out that, as many of these factors will prove difficult to influence, it is crucial that surgery is made as safe as possible, which includes reducing surgical site infection rates.

“CS carries several potential complications, which are explained at the time of signing the consent form. Infection is the most common potential problem (4% to 6%), with readmission to hospital a close second (5%). However, the readmission to hospital is invariably due to infection, so the two are, in fact, linked. Risk of haemorrhage requiring transfusion is low, as is trauma to the bladder or ureters, but the risk of thromboembolism is 3.6 times higher than those with a normal delivery,” she commented. She explained that, in terms of the symptoms associated with infection, discharge is common and is usually the first thing that a woman will notice and complain of. Dehiscence is not uncommon, but usually happens after release from hospital. Women do not usually have pyrexia or malaise with wound infection alone, and there is usually some other co-existing source of infection if this is the case. Abscesses are rare, she added, although wound haematomas often precede either discharge from the wound or dehiscence.