Updated May 02, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

 What is a Lumbar Puncture?

A lumbar puncture, also called an LP or a spinal tap, is a procedure that doctors use to collect fluid from the spinal column. During a spinal tap, a needle is placed between the bones in the back and into the spinal column. A small amount of spinal fluid is removed, and the needle is withdrawn. 

Why Are Spinal Taps Done in Babies?

Most lumbar punctures in babies are done to check for meningitis, an infection in parts of the brain and spinal column.

Meningitis is a very serious infection, and only a spinal tap can test for this illness. 

Many parents are surprised to hear that their baby needs a spinal tap, especially if their baby doesn't seem very sick. However, spinal taps are an important test for babies who don't feel well. Common neonatal infections such as group B strep can easily travel to the spinal cord, but babies with meningitis don't always have signs of a brain infection. If a baby does have meningitis, it's important for doctors to diagnose it so they can prescribe the right antibiotics or other medication. 

In addition to testing for meningitis, there are other reasons to perform spinal taps in premature and sick babies. One important reason is to prevent hydrocephalus in babies with severe IVH. Doctors may use spinal taps to remove excess blood and spinal fluid to prevent or delay the need for a shunt. 

Benefits and Complications of Lumbar Punctures in Babies

Deciding whether or not to do a spinal tap is never an easy choice.

Lumbar punctures are invasive procedures with both benefits and risks. Doctors will weigh the risks of the procedure against the benefits to help them decide whether to do a lumbar puncture or not.

Spinal taps are a useful procedure with many benefits:

• Spinal taps can diagnose serious or even life threatening illness.
• Meningitis can only be diagnosed using a spinal tap.
• The results of a spinal tap can be used to prescribe the best treatment for your baby.

Although spinal taps are considered safe, there are still some potential risks.

• Spinal taps can be uncomfortable, but shouldn't be painful.
• Infection is a risk of any invasive procedure.
• Possible headache or bleeding can occur.
• Premature or sick babies may have a lower heart rate or oxygen saturation during a spinal tap.

Sources:

KidsHealth from Nemours. (2013). "Lumbar Puncture (Spinal Tap). Retrieved from http://kidshealth.org/parent/general/sick/lumbar_puncture.html

Srinivasan, L, Harris, M., & Shah, S. (2012). "Lumbar puncture in the Neonate: Challenges in Decision Making and Interpretation." Seminars in Perinatology. 445-453.