Standards for baby and toddler growth have been established by the World Health Organization. A newborn typically weighs between 7 and 7 ½ pounds (3.2 to 3.4 kg). Most term healthy newborns weigh between 5 pounds 11 ounces and 8 pounds 6 ounces (2.6 to 3.8 kg). A low birth weight is less than 2.5 kg (5 pounds 8 ounces) at full birth, and an above average birth weight is over 4.0 kg (8 pounds 13 ounces). Many things can affect a new-born’s birth weight. They include: How many weeks a pregnancy lasts: Babies born prematurely tend to be smaller, and babies born past term can be larger. Smoking: Mothers who smoke tend to have smaller babies. Gestational Diabetes: Diabetes during pregnancy can result in a larger than average baby. Nutritional status: Poor nutrition during pregnancy can result in a smaller baby, while excessive weight gain can result in a larger baby. Family History: Some babies are born smaller or larger, and it can just run in the family. Baby girls often weigh a little less than baby boys at birth. A single baby will probably be born weighing more than siblings who were delivered during a multiple pregnancy (twins, triplets, etc.) Gaining Weight During the First Year Again, every baby is unique, but here are some common expectations for the first year of life. Initial Two Weeks Both breastfed and bottle-fed babies typically lose weight during the first few days of life. A infant who is solely breastfed may lose up to 10% of his body weight, whereas a baby who is bottle-fed may lose up to 5%. However, most infants regain all of the weight they have lost and reach their birth weight within two weeks. One month By One Month Most newborns will have gained a pound or so more than their birth weight by the first month. Infants start to establish a regular eating schedule at this age, are less drowsy, and have a stronger suck during feedings. Within six months For the first six months, newborns typically gain one pound on average per month. For females, the average weight at six months is roughly 16 pounds and ounces (7.3 kg), while for boys it is 17 pounds and ounces (7.9 kg). From One Year Weight gain moderately slows between six months and a year. By five to six months of age, most babies have doubled their birth weight, and by the time they are a year old, they have tripled it. What Else Do I Need to Know? Being little or large at birth does not guarantee that a baby will remain that way throughout childhood or into adulthood. Numerous tall teenagers were once little babies, and even the biggest baby in the family may become a small adult. Kids typically grow to be about the size of their parents by the time they are adults. The development of your child in the years to come will be greatly influenced by genetics, excellent diet, and your care. No matter how big, little, or normal your baby is at birth, you can count on them to continue growing quickly during the coming months.