Regression coefficients for variables that remained after backward stepwise elimination procedures in a multiple linear regression model predicting maternal BLL.

Overall R2 = 10.9%; p<0.001. Model was hierarchical with gestational age and haemoglobin entered in Block 1 and remaining variables in Block 2. Removed from the model (F≥0.100): social class, dietary iron intake, always lived in Avon. aThe Neighbourhood Quality Index (score 1–12) was calculated from a composite index of scores for ‘Lively’ ‘Friendly’, ‘Noisy’, ‘Clean’, ‘Attractive’ and ‘Polluted/dirty’ neighbourhood (a higher score indicates a higher quality neighbourhood). bReference: Certificate of Secondary Education (CSE)/no qualifications. cCaffeinated plus decaffeinated.