From the Guidelines
Babies should not have water until they are 6 months old, as breast milk or formula provides all the necessary hydration and nutrition before this age. Before 6 months, introducing water can be harmful, as it fills their tiny stomachs, reducing their intake of nutrient-rich milk, and potentially causing "water intoxication" where sodium levels become dangerously diluted 1. After 6 months, small amounts of water (1-4 ounces per day) can be offered in a sippy cup alongside the introduction of solid foods. The water helps babies learn to use cups and supports hydration as their diet expands. However, breast milk or formula should remain their primary source of nutrition and hydration throughout the first year of life.
When offering water to babies older than 6 months, plain tap water is appropriate - no need for bottled water, and avoid adding sweeteners, juice, or other additives. It's essential to note that the American Academy of Pediatrics recommends exclusive breastfeeding for the first 6 months, and introducing water or other fluids too early can interfere with this process. The study by Holliday and Segar provides a formula for calculating maintenance water needs in children, but this is more relevant for parenteral nutrition and not directly applicable to oral water intake in healthy babies 1.
In general, the total water requirements in children and infants beyond the neonatal period consist of maintenance needs, replacement of ongoing losses, and replacement of deficits, but for healthy babies, breast milk or formula is sufficient to meet these needs until 6 months of age. After 6 months, offering small amounts of water can help support hydration and the introduction of solid foods. It's crucial to prioritize breast milk or formula as the primary source of nutrition and hydration throughout the first year of life.
From the Research
Age of Introduction to Water
- The introduction of water to babies is a topic of interest, with various studies providing insights into the appropriate age for this introduction.
- According to a systematic review published in 2023 2, 86.2% of infants were around 6 weeks old, 44% were 1 month old, 77% were 3 months old, 2.5% were 4 months old, and 2.5 to 85% of the infants were around 6 months old when they first consumed water.
- The American Academy of Pediatrics recommends exclusive breastfeeding for the first 6 months, and introducing water or other fluids is not necessary during this period 2.
- However, the study also highlights that families introduce water to their infants at varying rates, and the factors affecting this situation need to be understood by healthcare professionals to provide appropriate education and interventions.
Health Implications
- Introducing water too early can lead to hypernatremic dehydration, a rare but serious condition in newborns and small infants 3, 4.
- Hypernatremic dehydration can occur due to inadequate breastfeeding or underfeeding, and it is essential for healthcare workers to monitor breastfed infants regularly to avoid serious morbidity and mortality 4.
- Breast milk provides complete nutrition and many bioactive health factors, and its unique microbiome plays a crucial role in promoting gut colonization of beneficial microbes and preventing pathogen adhesion 5.
Breastfeeding and Hydration
- Maternal body composition, hydration, and metabolic health can impact breastfeeding success, and adequate hydration is essential for lactation 6.
- The amount and distribution of water and adipose tissue are crucial for successful lactation, and various hormonal imbalances and metabolic disorders can increase the risk of delayed breastfeeding initiation, shortened breastfeeding duration, or insufficient milk production 6.