Identification of ‘hot spots’ of obesity and being underweight in early pregnancy in Liverpool

BACKGROUND: Obesity and being underweight in pregnancy are related to an increased risk of maternal and foetal morbidity, yet their prevalence is often unknown. The present study aimed to identify neighbourhoods with a higher than average prevalence or 'hot spots' of obesity and/or being underweight among first trimester pregnant women. METHODS: A database was compiled consisting of postcode, height and weight for 7981 women who had booked-in for antenatal care between July 2004 and June 2005 at Liverpool Women's Hospital. Body mass index (BMI) was calculated and women were categorised accordingly. Postcodes for 6865 cases across Merseyside were converted to geolocations (pin-points on a map) using conversion software (http://www.census.ac.uk/cdu/). RESULTS: There was a very high prevalence of being overweight (27%) and obesity (17%); 3.8% of women were underweight and probably malnourished (BMI < 18.5 kg m(-2)); and a further 10.7% of women were possibly malnourished (BMI < 20.0 kg m(-2). Deriving case density from the geolocations allowed visualisation and identification of six neighbourhoods with above average levels of obesity and three neighbourhoods had marked concentrations of both being underweight and obesity. CONCLUSIONS: These neighbourhoods, particularly those identified as 'hot spots' for both being underweight and obesity, include some of the most deprived wards in the UK. As dietetic intervention may help to promote optimal weight gain during pregnancy and improve dietary intake for pregnant women and their families, primary health care providers should target these localities with a high prevalence of low and high BMI as a priority.