IUGR stands for intrauterine growth retardation or intrauterine growth restriction. IUGR and SGA refer to the same process. There are many causes.
Some causes arise with the baby.
This is most likely true if the baby is abnormal with one or more severe problems in the development of organs. Infection of the fetus weeks to months before birth, called congenital infection. These babies have little reserve energy and oxygen. They may be more stressed with labor and delivery. They may have their first stool, called meconium, before birth.