“…Cheong et al 7 recruited infants with a birth weight of ,1,250 g or ,30 weeks' gestation; however, the mean gestational age of subjects in that study was 27.4 weeks, with SD of 1.9 weeks, and therefore it is unlikely to have included many infants of .32 weeks. Eight studies 6,11,21,25,28,29,36,38 accounted for size differences between different ethnic and racial groups, while social factors were considered in 15 studies. 7,8,10,[12][13][14]17,18,21,25,27,28,30,34,36 WHO standards suggest one set of growth curves is appropriate for children throughout the globe; however, this may underestimate the rate of microcephaly and overestimate the rate of large head size in Western European countries.…”