Proportions of long chain fatty acids in cord serum phospholipids (% of cord serum phospholipids, mean±SEM).

Phospholipids were extracted from cord serum and analysed by gas chromatography. Fatty acids of chain length 20–22 carbon atoms were analysed in all samples, while 16–18 carbon atom long fatty acids were assayed in samples of sufficient remaining quantity. Adolescents were assigned to any of the three diagnostic groups based on clinical examination at 13 years of age. Adolescents with atopic eczema had no other allergic manifestation; the same was true of adolescents with respiratory allergy. Non-allergic adolescents had no symptoms and no skin-prick test positivity to a range of common aeroallergens and food allergens (see Methods). P values given in italics signify higher levels of the fatty acid species in the infants who did not develop allergy.