From the Guidelines
Elevated alkaline phosphatase (ALP) in newborns is often a normal finding and typically doesn't require treatment. Newborns naturally have higher ALP levels than adults, with values up to 500 IU/L considered normal due to increased bone growth and development, as noted in a recent study 1. If levels are significantly elevated (above 500 IU/L), further evaluation may be necessary to rule out underlying conditions. Common causes include:
- Physiologic bone growth
- Certain medications
- Liver disorders
- Bone diseases like rickets Evaluation should include a thorough physical examination, review of maternal and birth history, and possibly additional tests like liver function tests, vitamin D levels, or imaging studies if clinically indicated, as suggested by the American College of Radiology 1. Most cases of mildly elevated ALP resolve spontaneously as the infant grows. Parents should be reassured about the benign nature of this finding in most cases, but follow-up testing may be recommended if levels remain significantly elevated beyond a few months of age or if the infant shows any concerning symptoms like poor weight gain, jaundice, or bone abnormalities. The pediatrician should monitor the infant's growth and development during routine well-child visits, taking into account the potential for ALP elevation to be of hepatic or nonhepatic origin, and consider measurements of GGT to indicate the source of elevated ALP, as discussed in the study 1.
From the Research
Elevated Alk Phos in Newborn
- Elevated alkaline phosphatase (ALP) in newborns can be caused by various factors, including benign transient hyperphosphatasemia, a condition characterized by greatly increased serum ALP without laboratory or clinical evidence of underlying bone or liver disease 2.
- This condition is usually identified incidentally during routine blood testing and resolves spontaneously, with no intervention 2.
- Other known causes of markedly elevated serum ALP should be excluded, especially bone and liver disease 2.
Diagnosis and Management
- In the case of an incidental finding of high serum alkaline phosphatase in an otherwise healthy infant or child with no other clinical or laboratory suspicion of bone or liver disease, it is recommended to repeat the alkaline phosphatase level within a few months to confirm the resolution of this condition 2.
- A "wait and see" approach is optimal when benign transient hyperphosphatasemia is suspected, in order to avoid unnecessary investigations and parental anxiety 2, 3.
- An algorithm can be utilized as a guide in a primary care setting to arrive at the diagnosis of transient hyperphosphatasemia and avoid further tests or referrals 3.
Differential Diagnosis
- Hypophosphatasia is a rare disorder due to a mutation in the ALPL gene encoding the alkaline phosphatase, leading to a diminished activity of the enzyme in bone, liver, and kidney 4.
- Elevated serum ALP in infants with parenteral nutrition-associated liver disease can reflect bone rather than liver disease 5.
- High alkaline phosphatase activity in preterm neonates has been associated with slower growth rate and reduced attained length at 9 and 18 months post term 6.