<div>Girls tend to be born with smaller and weaker backbones than boys, a new study has found. The finding may have implications years down the road.<br /><br />Researchers, writing in the August issue of The Journal of Paediatrics, did magnetic imaging studies that measured fat, muscle and bone in 70 healthy full-term newborns, 35 of them girls. Boys had slightly less fat and slightly more muscle than girls, but the difference was not statistically significant. <br /><br />Nor were there any significant differences between the sexes in weight, body length, head circumference, waist circumference or spinal length.<br /><br />But the girls’ vertebrae were, on average, 10.6 per cent smaller than the boys’, a difference independent of gestational age, birth weight and body length. There was no difference <br />between sexes in the size of other bones.<br /><br />As adults, women are up to four times as likely to sustain vertebral fractures as men, and the weakness depends more on the size of the vertebrae than on the density of the bone.<br /><br />The senior author, Vicente Gilsanz, a radiologist at Children’s Hospital Los Angeles, said that a girl’s slender and bendable spine may be a mixed blessing. It provides flexibility to allow upright walking during pregnancy, when the weight of a foetus stretches and bends the spine. But it also increases the risk for vertebral fractures later in life. <br /><br /><br /></div>
<div>Girls tend to be born with smaller and weaker backbones than boys, a new study has found. The finding may have implications years down the road.<br /><br />Researchers, writing in the August issue of The Journal of Paediatrics, did magnetic imaging studies that measured fat, muscle and bone in 70 healthy full-term newborns, 35 of them girls. Boys had slightly less fat and slightly more muscle than girls, but the difference was not statistically significant. <br /><br />Nor were there any significant differences between the sexes in weight, body length, head circumference, waist circumference or spinal length.<br /><br />But the girls’ vertebrae were, on average, 10.6 per cent smaller than the boys’, a difference independent of gestational age, birth weight and body length. There was no difference <br />between sexes in the size of other bones.<br /><br />As adults, women are up to four times as likely to sustain vertebral fractures as men, and the weakness depends more on the size of the vertebrae than on the density of the bone.<br /><br />The senior author, Vicente Gilsanz, a radiologist at Children’s Hospital Los Angeles, said that a girl’s slender and bendable spine may be a mixed blessing. It provides flexibility to allow upright walking during pregnancy, when the weight of a foetus stretches and bends the spine. But it also increases the risk for vertebral fractures later in life. <br /><br /><br /></div>
