Signs of dehydration in a newborn

A newborn may lose fluid through vomiting, diarrhea, fever, hot surroundings, or difficulty breastfeeding or taking formula. Watch for a baby who is hard to wake, feeds for a shorter time, refuses feeds, has a weak suck, or seems unusually floppy. Dry lips or mouth, darker urine, and a soft spot that looks more sunken than usual can add to concern.

Nappy counts vary with age, feeding, and the early days after birth, so a change from the baby’s usual pattern matters. Dehydration can occur with gastroenteritis, but the cause needs medical assessment.

Contact the baby’s doctor or maternity service promptly if feeding or wet nappies decrease. Offer breastfeeds or prepared formula as advised, and do not dilute formula or give water, juice, or homemade rehydration drinks unless a clinician specifically recommends them. Record feeds, vomiting or diarrhea, and wet nappies to share during the assessment.

Seek urgent care if the newborn is difficult to wake, cannot feed, has repeated vomiting, very few or no wet nappies, a dry mouth, breathing changes, marked weakness, a sunken soft spot, or feels unusually hot or cold. A newborn with possible dehydration should not wait for symptoms to become severe.

Ask: Is feeding adequate? How many wet nappies should we expect at this stage? Could illness be causing fluid loss? Should feeding be observed? What exact signs mean we should return immediately?