The tiny newborn you hold in your arms will grow an impressive amount her first year of life. According to Nemours Foundation, most babies triple their birth weight and grow in length by around 50 percent. Healthy babies enter the world in a variety of weights and sizes. Medical experts offer guidelines on how much weight your baby should gain.
Newborn Weight and Size
Healthy babies carried to term generally weigh between 6 lbs, 2 oz and 9 lbs, 2 oz, with average length between 19 to 21 inches. Premature infants — those born at a gestational age of 37 weeks or less — tend to be smaller, while those born past the due date tend to weigh more and be larger. According to the National Institutes of Health, it’s common for healthy babies to lose a a little bit of water weight during the first few days of life before they start gaining weight.
Healthy Weight Gain
For the first 6 months of your baby’s life, you can expect him to gain anywhere between 5 and 7 oz a week and grow 1/2 to 1 inch every month, says Mayo Clinic. From 6 months to a year, weight gain and growth slow down slightly. Expect 3 to 5 oz of weight gain every week and an increase in length of 3/8 to 1 inch every month. Your baby’s birth weight can double by the time he reaches the age of 5 or 6 months; by the time his first birthday rolls around, it can triple.
Premature babies may need a stay in the neonatal intensive care unit to make sure that they receive the right amount of food and achieve appropriate weight gain. Unlike healthy infants, who lose a small amount of weight right after birth, premature babies should immediately start gaining. The right amount of weight depends on several factors, such as the baby’s gestational age, size and overall health. According to the NIH, premature infants are weighed each day. Generally speaking, a premature baby should gain 1 oz per day for every pound she weighs.
Babies whose weight or rate of weight gain don’t match up to infants of the same age and sex “fail to thrive.” Delayed growth can be caused by inadequate nutrition, a chronic disease, infection or genetic abnormalities, such as Down syndrome, says the NIH. Often, these children are delayed in other developmental areas as well and fail to meet appropriate developmental milestones for sitting up, standing and walking.
Steady weight gain is a sign that your baby is getting enough to eat. Newborns should be fed on demand, around the clock; most need to nurse between 8 and 12 times each day every 2- to 3-hour interval, says MayoClinic. If you’re concerned that your baby isn’t gaining enough weight, bring this to his pediatrician’s attention during well-baby check-ups. Your infant’s doctor uses a standard growth chart to diligently document your child’s weight gain, growth and development. Even a healthy baby can stop putting on weight — or even lose weight — for a short while; however, MayoClinic.com indicates that his pediatrician isn’t likely to be concerned unless your infant doesn’t show adequate progress from one doctor’s visit to the next.