Obesity, defined as a body mass index of 30 kg/m2 or more, has reached epidemic proportions globally, with more than one-and-a-half billion adults overweight and at least 500 million clinically obese. The prevalence of obesity in the UK has increased by over 300% since 1980. In the UK 24% of adult women are obese and one in six women at an antenatal booking clinic is obese.
Obesity has the potential for several detrimental effects on both the mother and the baby. Obese mothers are more likely to develop pre-eclampsia and eclampsia, gestational diabetes and venous thromboembolism. In addition, obese pregnant women are more likely to be induced, often resulting in complicated deliveries such as emergency Caesarean section and shoulder dystocia. Obesity significantly increases the risk of maternal mortality during or after pregnancy. Babies born to obese mothers are at an increased risk of congenital abnormalities, preterm deliveries and stillbirth, and children exposed to maternal obesity are at an increased risk of developing metabolic syndrome in later life.
The aim of this work was to assess the extent and potential for the prevention of adverse impacts of obesity in pregnancy. The specific objectives were to: summarise the literature on maternal obesity and adverse pregnancy outcome; perform an epidemiological analysis using local data of obesity in pregnancy; conduct a systematic review of existing evidence on lifestyle interventions for obesity in pregnancy; and to develop and evaluate a multi-component pilot study for a community-based intervention for maternal obesity in South London.
Analysis of delivery data from South London between January 2004 and May 2012 showed the overall prevalence of maternal obesity to be 15%, with considerable variation by ethnic group. There was a strong association between rising body mass index and risk of adverse pregnancy outcome, especially diabetes. The effect of obesity on diabetes in pregnancy was more pronounced in Asians and Orientals compared to other ethnic groups. Calculations of population attributable risk fractions showed that, if we were able to prevent obesity before pregnancy in this population, around one-third of diabetes in pregnancy could be prevented. The data alluded to the fact that the benefit of obesity reduction would be greater in Blacks than in other ethnic groups because of the higher prevalence of obesity in this group.
A complex community-based lifestyle intervention called the Community Activity and Nutrition (CAN) programme was developed for delivery by health trainers in children’s/Sure Start centres. The research showed that it is feasible to deliver the CAN intervention in children’s/Sure Start centres (Effra in Brixton, Jessop in Herne Hill and Jubilee in Tulse Hill) in an Inner London socially deprived community. The pilot study encountered problems with recruitment resulting from understaffing and lack of participant time. However, once recruited, retention on the programme was good. There was some evidence that the intervention improved selected clinical outcomes. Further work is ongoing to establish the clinical and cost effectiveness of the intervention. If CAN is shown to be clinically effective and cost-effective, the translation of this research and adoption by policy makers into the wider community may help to ameliorate the adverse outcomes associated with obesity in pregnancy
