Numerous. The sooner you can begin breastfeeding your premature baby, the better. Skin to skin contact will help your baby grow, regulate her breathing, and solidify your bond. Even if you can't breastfeed right away, pumped breast milk given to your preemie will aid in her brain development, decrease the likelihood of necrotizing enterocolitis, and provide her with much needed antibodies.
Low allergy. Low introduction of allergy to cows milk, and the immune system antibodies transferred from mom to child to protect the child from infections that are going around. This is not something that is put or can be put in formula.