Obesity in pregnancy - impact and challenges for critical care nursing.

Planning for the H1N1 epidemic put the focus on a sector of the health service population not routinely considered in critical care – pregnant women. There is however a more ‘silent’ epidemic that has considerable implications for both general and neonatal intensive care – maternal obesity. Whilst H1N1 is routinely considered to have implications for intensive care resources and staff education, the same level of risk management is not applied to maternal obesity. Obesity is reaching epidemic proportions globally, not least in women of reproductive age with an increasing prevalence of maternal obesity, defined as obesity in pregnancy (National Obesity Observatory, 2010). Nearly 1 in every 1000 women giving birth in the UK is extremely obese [defined as body mass index (BMI) 50 kg/m2 or higher]; these women are known to have poorer outcomes. In a national cohort study, women with BMI ≥ 50 kg/m2 were estimated to have an increased risk of intensive care unit (ICU) admission (adjusted odds ratio 3·86, 95% CI 1·41–10·6) as well as pre-eclampsia (adjusted odds ratio 4·46, 95% CI 2·43–8·16) and gestational diabetes (adjusted odds ratio 7·01, 95% CI 3·56–18·8) (Knight et al., 2010). Further, a study comparing different severities of obesity with non-obese women demonstrated an impact on risk factors such as gestational hypertension (30·9% versus 9·0%, p < 0·001, odds ratio 4·5, 95% CI 4·1–5·00) (Joy et al., 2009). A recent meta-analysis showed a significant relationship between maternal obesity and duration of hospital stay, haemorrhage, infection and infants requiring Neonatal Intensive Care Unit admission (Heslehurst et al., 2008). Obesity was also a significant risk factor for maternal morbidity or near miss (odds ratio 3·0, 95% CI 1·7–5·3) in a chart review undertaken in the USA (Goffman et al., 2007) and for maternal morbidity in a larger study undertaken in the UK (adjusted odds ratio 2·73, 95% CI 1·15–6·46) (Kayem et al., 2011). Maternal obesity has also been associated with maternal deaths either directly or indirectly related to pregnancy. In the report ’Saving Mothers Lives’ (Centre for Maternal and Child Enquiries, 2011) 47% of mothers who died of direct causes, sepsis, pre-eclampsia, thromboembolism, amniotic fluid embolism, haemorrhage and anaesthesia were overweight or obese as were 50% of the women who died from indirect causes such as cardiac disease and other pre-existing medical conditions, for example diabetes and epilepsy. Of those women who die, some die post birth and others before; in antenatal patients therefore there will be two patients, the mother and the foetus. The consequence of this may be an increased risk of foetal compromise in utero or neonatal death shortly after birth with foetal wellbeing linked to maternal health: when the mother’s condition is stable so is the foetus. The outcome of the foetus of a critically ill mother has been reported in descriptive studies (SeloOjeme et al., 2005). A detailed retrospective cohort study concluded that for pregnant women who receive critical care there is a significant effect on foetal and neonatal outcome ranging from foetal loss, neonatal death to complications associated with prematurity (Cartin-Ceba et al., 2008). The care and treatment of critically ill pregnant and post-birth women presents complex issues to the critical care team owing to the physiological adaptations of the maternal and foetal physiology associated with pregnancy which are compounded in the obese pregnant/post-birth women. For example, the usual physiological changes in pregnancy, such as an increase in cardiac output, heart rate, stroke volume and circulating blood volume are all further increased with obesity (Roofthooft, 2009). Furthermore, obesity research has shown that there is an association with increased peripheral resistance, chronic hypertension, increased blood velocity and plasma volume which could lead to impaired systolic and diastolic left ventricular function, which can contribute to maternal complications in the obese pregnant woman (Schunkert, 2002). A survey in the UK by Intensive Care National Audit and Research Centre (2009) highlighted that 11·4% of all women of reproductive age, defined as 16 – 50 years, admitted to critical care were obstetric patients. Of these 80% were reported as recently pregnant; the most commonly reported obstetric reason for admission was haemorrhage and the non-obstetric reason was pneumonia. As no BMI data were included in this analysis, the impact of obesity is unknown. However, given the epidemiological trends reported earlier, these admissions are likely to increase. The complexity of a critically ill pregnant/post-birth obese woman poses specific challenges to all critical care staff involved in the care of the woman and the family not only in relation to physical support but also psychological support. Evidence is accumulating showing that critically ill patients suffer high levels of stress emotions such as fear, anxiety, loneliness, depersonalisation, and panic; for the pregnant and post-birth woman