Reduced urine output in infants

Reduced urine output in infants: An important sign of dehydration

The number of wet diapers per day is one of the most important and objective indicators of an infant's hydration status. A reduction in urination frequency (oliguria) is the first and most reliable signal that the child's body has begun to experience fluid deficit and has switched to an "economy mode".

What is happening in the body?

The kidneys are the primary organ that regulates water balance. When the body begins to sense dehydration, special receptors in the brain trigger the production of antidiuretic hormone (ADH). This hormone acts on the kidneys, causing them to maximally reabsorb (draw back into the bloodstream) water from the primary urine. As a result, the volume of final urine excreted decreases significantly, and it becomes more concentrated.

What to watch for?

Normally, an infant should wet at least 5-6 diapers per day. Concerning signs include:

• Dry diaper for 6-8 hours.
• Fewer than 4-5 wet diapers in 24 hours.
• Very small amount of urine, diaper barely damp.
• Dark, deep yellow urine color with a strong odor.

Reduced urination is a key symptom of dehydration. If this symptom is combined with dry mucous membranes and lethargy, it requires immediate rehydration and a consultation with a physician.