Gender and Survival: Girl Babies Less Likely to Suffer from Neonatal Complications

A recent study conducted by researchers from the Robinson Research Institute examines why boys are more likely than girls to be born preterm or suffer from certain neonatal problems.

"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," said senior author of the paper professor Claire Roberts, leader of the fetal growth research priority for the institue, via a press 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 4-4.5kg or 8 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," she added. 

Follwoing the examination of 300 placenta samples, researchers found that over 140 genes were expressed differently across the samples from both genders.

"Our results suggest that there is a distinct sex bias in the regulation of genes in the human placenta," said lead study author Sam Buckberry of the University of Adelaide, via the release."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."

As the findings demonstrate the development and survival strategies for both genders, the study results could help as a guide for future sex-specific therapeutics for pregnant women and babies.

The findings were published in the journal Molecular Human Reproduction.