Could be genetic if the dam or sire is small.
If the mother has been ill or undernourished.
Crack.
Genetics. MA's have been bred to have low birthweights.
The low birth weight is less than 2500 grams
I only know one way i think if the mother drinks a lot (achoholic) it can affects the babies growth. There are many other ways, but that's the only one i know. There are many reasons babies come into...
depends on the kind.