Babies can have low blood pressure for many reasons. It is especially common in preemie babies just after birth. Reasons for low blood pressure include:
blood loss before or during delivery
fluid loss after delivery
infection
medications given to the mother before delivery
Sometimes it is not known why a baby's blood pressure is low. Low blood pressure is seen often in babies who have Respiratory Distress Syndrome.
a baby may be given extra fluid, often containing albumin, by vein.
a baby can be placed on a medication to increase blood pressure. These drugs are referred to as "pressors".
a baby may be transfused with blood from the blood bank. This is most often done if the suspected cause of low blood pressure is blood loss.