Does my newborn need water?

Why does a breastfed baby not need water?

Breast milk is mostly water and changes to meet a baby’s fluid and nutrition needs. The WHO advises offering more breastfeeds, rather than water, to babies under 6 months, even on hot days.

A baby who wants to feed again soon may be responding to warmth, cluster feeding, or a need for closeness. Do not assume this alone means dehydration or low milk supply; swallowing, nappies, weight monitoring, and overall wellbeing give more context.

How is water used for a formula-fed baby?

Use water only to prepare formula, with the exact water-to-powder ratio given by the manufacturer. Adding extra water does not make formula safer. It can mean your baby gets too little nutrition and can disturb the body’s salt balance. Using less water is not safe either.

Advice about preparing formula and water safety can differ by country, water source, and product instructions. Follow the label and the advice of your baby’s healthcare team. In the UK, NHS guidance says to make each feed with freshly boiled tap water that has cooled for no more than 30 minutes, so it remains at least 70°C when mixed with powder.

What can you do in hot weather?

Avoid overdressing your baby, keep the room comfortably cool, and offer the breast more often if your baby is breastfed. NHS guidance says formula-fed babies under 6 months may need small sips of cooled boiled water during hot weather as well as their usual milk feeds. This is separate from formula preparation: never add extra water to the formula itself.

A marked decrease in wet nappies, dry mouth, fewer tears, difficulty waking, or unusual sleepiness should not be put down to hot weather alone. If these happen with vomiting or diarrhoea, seek healthcare advice promptly.

What should you avoid for hiccups or fussiness?

Do not give water, sugar water, herbal tea, or fruit juice to stop hiccups, ease gas, or settle a baby under 6 months. These can replace breast milk or formula, and some products may not be suitable for babies.

Hiccups often stop on their own. If your baby seems uncomfortable after a feed, holding them upright calmly and burping them if needed may help. Seek assessment if they have repeated coughing, turn blue, or cannot feed.

Do vitamins, medicines, or oral rehydration solution count as water?

A vitamin or medicine drop recommended by a doctor is not the same as routinely giving water and should be used at the recommended dose. Oral rehydration solution is also different from plain water; during vomiting or diarrhea, give it only if a healthcare professional advises that it is suitable for your baby’s age and situation.

Do not prepare a salt-and-sugar mixture at home, dilute formula, or try to replace fluid loss with plain water. Fluid loss can worsen quickly in a newborn.

How can you tell whether your baby is getting enough fluid?

Do not judge by one nappy alone. Consider the pattern of wet nappies expected for your baby’s age, effective swallowing, feeding frequency, weight checks, and alertness when awake. Nappy expectations change quickly in the first days, so ask your healthcare team what is expected at your baby’s age.

If your baby is feeding well, has their usual nappies, and seems well, hot weather alone is not a reason to add water. If you are worried, sharing the last 24 hours of feeds and nappies can help with assessment.

What can you do today?

In hot weather, dress your baby in light layers and offer the breast more often if they are exclusively breastfed.

When preparing formula, follow the exact water and powder measurements on the container; do not add water to the bottle afterwards.

Note feeds and wet nappies over the last 24 hours. If they decrease noticeably, seek healthcare advice instead of offering water.