Your baby will grow tremendously in his first few months. If he seems smaller than others his age, you may wonder if he's "behind" or even start to worry that he's not getting enough to eat. In most cases, you have no reason to worry. While newborns grow in similar patterns, your baby will grow according to his own genetic imprint, by his own calendar.
Weight and Length
Most full-term newborns weigh between 6 pounds, 2 oz. and 9 pounds, 2 oz. and their average length is between 19 to 21 inches, according to KidsHealth. However, since all babies are born with additional fluid, your newborn may initially lose between 7 and 10 percent of her birth weight but regain it within the first two weeks. After weight is regained--and up until about six months of age--she may gain between 5 and 7 oz. each week and grow up to an inch per month, according to the Mayo Clinic.
Growth Factors
Factors besides genetic makeup influence your newborn's growth. For example, poor maternal nutrition may affect a baby's birth weight and influence how he grows later on. Another factor is gender; although most babies are within the same weight range at birth, boys tend to be larger than girls later in infancy. Moreover, a baby with medical problems such as infections or birth defects may grow differently from other infants of the same age and gender. Regardless, your baby's initial birth weight doesn't necessarily predict his future growth or size.
Needs
Your newborn's growth depends on adequate nutrition and sleep. A round-the-clock routine of eating and sleeping will sustain her rapid growth. She will eat every two to three hours and sleep in about eight small stretches that will give her between 16 and 17 hours of sleep each day. She may develop her own sleeping and eating patterns early on, but they are subject to change based on her needs. By the time your baby is three months old, she may be able to sleep "through the night," for at least five hours at a time.
Helpful Reflexes
Your baby was born with reflexes, or involuntary responses, that aid him in growing in his early months. One of these reflexes is the rooting reflex, which is initiated when the corner of his mouth is touched. In response, he will turn his head and open his mouth in an attempt to find the bottle or breast. Another reflex is the suck reflex, which begins when the roof of your baby's mouth is touched.
Gauging Growth Patterns
Pediatricians use growth charts to gauge infant growth patterns and compare them with other infants of the same age and gender. Whether your newborn is in the 5th percentile or the 95th percentile doesn't usually matter as long as she is growing at a steady rate.
