A comparison of antenatal classifications of 'overweight' and 'obesity' prevalence between white British, Indian, Pakistani and Bangladeshi pregnant women in England; analysis of retrospective data.

Background: Maternal obesity increases women's risk of poor birth outcomes, and statistics show that Pakistani and Bangladeshi women (who are born or settled) in the UK experience higher rates of perinatal mortality and congenital anomalies than white British or white Other women. This study compares the prevalence of maternal obesity in Indian, Pakistani, Bangladeshi and white British women using standard and Asian-specific BMI metrics.

Method: Retrospective cross-sectional analysis using routinely recorded secondary data in Ciconia Maternity information System (CMiS), between 2008 and 2013. Mothers (n = 15,205) whose ethnicity was recorded as white British, Bangladeshi, Pakistani or Indian. Adjusted standardised residuals and Pearson Chi-square.

Main Outcome Measures: Percentage of mothers stratified by ethnicity (Indian, Pakistani, Bangladeshi and white British) who are classified as overweight or obese using standard and revised World Health Organisation BMI thresholds.

Results: Compared to standard BMI thresholds, using the revised BMI threshold resulted in a higher prevalence of obesity: 22.8% of Indian and 24.3% of Bangladeshi and 32.3% of Pakistani women. Pearson Chi-square confirmed that significantly more Pakistani women were classified as 'obese' compared with white British, Indian or Bangladeshi women (χ  = 499,88 df = 9, p < 0.001).

Conclusions: There are differences in the prevalence of obese and overweight women stratified by maternal ethnicity of white British, Indian, Pakistani and Bangladeshi. Using revised anthropometric measures in Indian, Pakistani and Bangladeshi women has clinical implications for identifying risks associated with obesity and increased complications in pregnancy.