 The mothers will be followed up in the hospital before discharge, at the postnatal clinic at 1 and 6 weeks, and at 3,6 and 12 months. The mothers blood 1 ml will be taken at 1 and 6 weeks and breast milk 20 mls will be collected at 1 week, 6 weeks, 3 months, 6 and 12 months after delivery as long as mothers breastfeeds.The maternal serum and breast milk total lipids will be extracted and fractionated using micro-extraction and semi-preparative liquid chromatography fraction methods. The fatty acid methyl esters will be separated, using liquid chromatography and capillary electrophoresis coupled mass spectrometry, and tje n-6 and n-3 fatty acid methyl esters identified by comparison with retention times and mass charge ratio information of pure reference substances sigma Aldrich Sweden AB,Stockholm, Sweden. 