Unexplained Weight Loss in Infants

The early months of a baby's life often involve rapid growth in weight and height, but in some infants, this process is stunted or reversed. Unexplained weight loss can have a negative impact on your newborn's health. A pediatrician can help you rule out possible causes behind your child's weight loss.

Nutrition Problems

A pediatrician may diagnose your little one with "failure to thrive," a term used to describe a baby's slow growth, according to Kids Health, a child development site 14. A baby may not be getting enough to eat. Breastfeeding mothers may not produce enough milk for their growing babies, or parents may overestimate how much food their baby is getting. Problems that make eating difficult or painful, like deformities involving the mouth, teeth or tongue, may also be responsible for your infant's weight loss.

Problems with Malabsorption

Your little one may be getting plenty to eat, but losing weight anyway, according to the American Academy of Pediatrics. Diarrhea, bruising, weight loss and vomiting may be among the symptoms your infant experiences if he has malabsorption problems. Malabsorption may be the result of an infection, and a pediatrician may prescribe antibiotics. In other cases, your child may need to take medications for an overactive intestine. Your infant may need to eat a special diet for life to prevent malabsorption from occurring again.

Celiac Disease

If someone in your family has celiac disease, your newborn may inherit it 3. Someone with celiac disease has trouble digesting gluten, which is found in grain products, says Kids Health 34. Infants may have diarrhea, stomach pain and weight loss if their diet consists of gluten products. These children will never be able to eat gluten, and a pediatrician will recommend a gluten-free diet. Children are usually diagnosed with celiac disease beginning at about 6 months old, when they often make the transition to solid foods 3.


Autoimmune diseases that your infant is born with may play a role in unexplained weight loss. Baby girls are considerably more likely than baby boys to have lupus, which causes the body to attack its healthy cells, says Kids Health 14. Vomiting, diarrhea, sun sensitivity, weight loss, swollen glands and joint and muscle problems are common lupus symptoms. Your daughter's pediatrician will refer her to a rheumatologist if lupus is suspected, according to the AAP. Medications and proper diet are common remedies for lupus.