Macrosomia occurs when newborns weigh in above 8lbs.
It affects around four per cent of babies born in the UK. Its US prevalence is unknown.
The average newborn weighs around 7lbs.
Babies with macrosomia have a greater risk of suffering birth complications, which increases significantly at weights above 9lbs.
Some women are genetically predisposed to have large babies, with the infants’ weights generally increasing with each successive pregnancy.
Other risks factors include the mother being obese, having poorly managed diabetes, gaining an excessive amount of weight during pregnancy or being more than two weeks past her due date.
Male, hispanic babies are more likely to have macrosomia.
The condition increases women’s risk of a difficult vaginal delivery, which may lead to tearing, blood loss and damage to their tailbones.
Babies with macrosomia who are born vaginally may get stuck in the birth canal, causing them to break their collar or arm bones, or suffer nerve damage.
Source: Baby Center