Baby Birth Weight Statistics

Growth and Development Basics

Newborn Baby
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The mean or average birth weight in the United States is about 3,389g or 7 lb, 7.5 oz.

However, any birth weight of a term newborn between 5 lbs, 8 oz, and 8 lbs, 13 oz is considered to be normal.

Baby Birth Weight Statistics

In 2013, there were:

  • 55,947 births at 1499g or less (3.3 pounds or less)
  • 61,992 births from 1500g to 1999g (3.3 to 4.4 pounds)
  • 200,908 births from 2000g to 2499g (4.4 to 5.5 pounds)
  • 727,987 births from 2500g to 2999g (5.5 to 6.6 pounds)
  • 1,546,274 births from 3000g to 3499g (6.6 to 7.7 pounds)
  • 1,071,007 births from 3500g to 3999g (7.7 to 8.8 pounds)
  • 276,592 births from 4000g to 4499g (8.8 to 9.9 pounds)
  • 39,353 births from 4500g to 4999g (9.9 to 11 pounds)
  • 4,746 births from 5000g to 8165g (11 to 18 pounds)

Although most babies are born between 3,000g (6 lbs, 9 oz) and 3,499g (7 lbs, 11oz), there is a broad range of sizes for the 4 million babies born each year - ranging from just under 1 pound to more than 16 pounds. The smallest babies are typically the most premature.

Baby Birth Weight Trends

It is well known that kids are getting bigger, with the childhood obesity epidemic continuing to be a problem. And some experts now think that some of the obesity problems can start as early as the newborn period. So are newborn babies getting bigger, too?

Recent trends in average birth weight include:

  • 1990 - 7 lbs, 9.4 oz
  • 1995 - 7 lbs, 9.17 oz
  • 2000 - 7 lbs, 8.95 oz
  • 2005 - 7 lbs, 7.54 oz

As you can see, statistics show that babies are actually getting a little smaller, and this is not thought to be due to more premature babies or other independent factors.

Newborn Weight Classifications

Depending on their weight at birth and their gestational age, using special growth charts, babies are typically classified as being:

  • Small for gestational age (SGA) - birth weight less than the 10th percentile
  • Appropriate for gestational age (AGA) - normal birth weight
  • Large for gestational age (LGA) - birth weight greater than the 90th percentile
  • Intrauterine Growth Restriction (IUGR) - lower birth weight than expected for a baby's gestational age
  • Extremely low birthweight (ELBW) - birthweight less than 1000 grams or 2.2 pounds
  • Very low birthweight (VLBW) - birthweight less than 1500 grams or 3.3 pounds
  • Low birthweight (LBW) - birthweight less than 2500 grams or 5.5 pounds
  • Normal birthweight - between 5 lbs, 8 oz and 8 lbs, 13 oz
  • High birth weight (HBW) - birthweight of more than 4000g or 8.8 pounds

Why all of the different classifications? Many can be used together. For example, a premature baby could be born low birthweight or every extremely low birth weight, but still be at an appropriate weight for his gestational age.

On the other hand, a full-term baby who was born at 2,500g (5.5 pounds) would likely be classified as being both SGA and IUGR.

What To Know About Average Birth Weights

In addition to these tips, other things to know about a babies average birth weight include that:

  • There were 3,988,076 births in the United States in 2014, which was up about 1% from 2013.
  • Teen birth rates are at historic lows.
  • The mean age that mothers have their first baby continues to rise and is now at 26.3 years.
  • Rates for cesarean deliveries and preterm births both declined in 2014.

Most importantly, remember that many factors influence how much your baby will weigh when he or she is born, from the length of your pregnancy to genetic factors. And whether you think that your baby is too big, too small, or just right, a baby's size at birth doesn't necessarily predict their size when they get older.

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