Fever in a Newborn
Fever in babies can be from infection, illness—or other causes that may be even more serious. Call your doctor immediately if your baby is younger than 3 months and has a rectal temperature of 100.4 degrees or higher.
Behavior Changes
Although a baby's activity level, appetite, and cries normally vary from day to day, even hour to hour, a distinct change in any of these areas may signal illness.
Skin Color Changes
The color of a baby's skin can often help identify possible problems in another area of the body. It is important for you to call your doctor if certain skin color changes occur.
Breathing Problems
Changes in a baby's breathing rate or pattern, using other muscles and parts of the chest to breathe, or changes in color may mean the baby is having respiratory distress and needs immediate medical attention.
Gastrointestinal Problems
Some babies may constantly spit up all or most of every feeding, or gag and choke during feedings. This may be caused by reflux.
Jaundice
Over half of all newborns develop some amount of jaundice, a yellow coloring in their skin, during the first week. This is usually a temporary condition, but may be a more serious sign of another illness.
Colic
Colic is defined by the "rule of three": crying at least 3 hours per day, more than 3 days per week, and for 3 weeks duration or more.
Natal Teeth
Natal teeth are teeth that are present when the infant is born. They are usually the infant's primary teeth (or baby teeth) that have come in early.