Lower levels of albumin in blood may indicate different systemic problems.
Albumin is produced in liver, so, diseases affecting the liver can result in low levels of albumin in blood.
It can also result from kidney disease, which allows albumin to escape into the urine.
When there is a malnutrition (an improper or inadequate diet and nutrition) and malabsorption syndrome, the low levels of albumin are expected.
Actually, your baby can have a protein losing enteropathy, when there is a excessive leakage of plasma proteins into the lumen of the gastrointestinal tract (bowels).
The cause for this disorder can be a gastrointestinal disease, or a systemic disease.
If this is your baby problem, the loss of proteins may affect not only albumins, but also the proteins (immunoglobulins) important to fight infections, making your baby more prone to develop ones.