The diagnosis of neonatal meningitis often rests on microscopic and biochemical findings in the cerebrospinal fluid (CSF).

There is ongoing uncertainty about age-related normal values for CSF findings in neonates, and many previous studies have included infants in whom antibiotics were administered before lumbar puncture or in whom viral meningitis was not excluded.

A systematic search was done using MEDLINE and EMBASE to identify original studies which investigated CSF normal values in either healthy neonates or febrile neonates in whom bacterial and viral meningitis were reliably excluded.