Why does a baby's weight decrease after birth?

In general, a baby's weight loss after birth may be caused by factors such as fluid loss, breathing, malnutrition, bowel movements, and limited breast milk intake. If the baby shows signs of discomfort, it is recommended to seek medical attention promptly. The specific reasons are as follows:

1. Fluid loss: After birth, newborns lose water through breathing, skin evaporation, and urination. Due to their limited food intake, this fluid loss can lead to a decrease in body weight.

2. Breathing: Newborns begin using their lungs to breathe independently instead of relying on maternal oxygen supply. This transition process may result in reduced body water content, thereby affecting body weight.

3. Malnutrition: If a newborn does not consume enough breast milk or if the mother has insufficient milk production, the infant may become malnourished, leading to weight loss. It is recommended that breastfeeding mothers eat nutrient-rich foods to support the baby’s nutritional needs and promote healthy development.

4. Bowel movements: Shortly after birth, newborns pass meconium, which consists of waste accumulated during fetal development in the womb. The elimination of meconium also contributes to temporary weight reduction.

5. Limited breast milk intake: During the first few days of life, a newborn's intake of breast milk may be relatively small due to their limited stomach capacity and the time required to establish effective breastfeeding techniques.

In daily life, breastfeeding mothers are advised to consume foods rich in protein, vitamins, minerals, and other essential nutrients—such as eggs, lean meat, tomatoes, and apples—to help meet energy requirements and maintain overall health.