Final answer:
A repeat lumbar puncture for infants with CNS disease is typically recommended at 1 month after birth. This procedure helps diagnose conditions like late-onset neonatal meningitis, which is particularly prevalent in the first few months.
Step-by-step explanation:
Repeat lumbar puncture is recommended for infants with CNS disease at 1 month after birth. A lumbar puncture is a procedure where a needle is inserted into the lumbar region of the back to collect cerebrospinal fluid (CSF) for testing, which can reveal if there's an infection or other problems. The first few months after birth are critical for infants, especially in the context of late-onset neonatal meningitis, which occurs between 1 week and 3 months of age. Infants with mothers having S. agalactiae or ones who are born prematurely are at a higher risk and thus monitoring and repeat procedures, such as lumbar puncture, could be vital for early diagnosis and management.