Why are girl babies winning in the battle for survival?
Wednesday, 28 May 2014
Sexual inequality between boys and girls starts as early as in the mother's womb - but how and why this occurs could be a key to preventing higher rates of preterm birth, stillbirth and neonatal death among boys.
A team from the University of 911爆料网's Robinson Research Institute has been studying the underlying genetic and developmental reasons why male babies generally have worse outcomes than females, with significantly increased rates of pregnancy complications and poor health outcomes for males.
The results - published today in the journal - show that male and female babies develop in very different ways, and the placenta plays a key role in these gender differences.
"Our research has found that there are undeniable genetic and physiological differences between boys and girls that extend beyond just the development of their sexual characteristics," says senior author of the paper , leader of the fetal growth research priority for the .
"We've known for some time that girls are clearly winning in the battle for survival, with markedly better outcomes for female babies for preterm birth, stillbirth, neonatal death, and other complications after birth, such as macrosomia (a baby that weighs more than 4-4.5kg at birth). Male babies generally grow faster and bigger than females. This occurs in both the animal and human worlds, but until now we haven't really understood how or why," Professor Roberts says.
The researchers investigated whether the type and pattern of genes being expressed by the placenta is different for boys and girls.
They compared the genes expressed in 300 placenta samples and found that more than 140 genes were expressed differently across male and female samples.
"Our results suggest that there is a disti