Researchers looked into why female newborns have better survival rates than males.
A research team looked at the underlying genetic reasons as to why females have a better survival rate at birth, a University of Adelaide news release reported.
"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 Professor Claire Roberts, leader of the fetal growth research priority for the Robinson Research Institute said in the news release.
"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 [four to 4.5kg or [eight] pounds 13 ounces 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 said.
The team looked at certain patterns of genes displayed in the placenta differed between baby boys and girls.
They looked at the genes in 300 placenta samples and found differences between male and female newborns in over 140 of the present genes.
"We found that with female babies, there is much higher expression of genes involved in placental development, the maintenance of pregnancy and maternal immune tolerance," lead author and University of Adelaide PhD student Sam Buckberry, said in the news release.
"This suggests that girls are more likely to adopt a risk-averse strategy towards development and survival, and it goes some way to explaining the differences in male and female development in the womb," he said.
The findings could help lead to sex-specific therapies to help raise the survival rate in newborn males.
