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URL of this page: https://medlineplus.gov/birthweight.html

Birth Weight

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Summary

What is birth weight?

Birth weight is the first weight of your baby, taken just after being born. A low birth weight means that the baby is less than 5 pounds, 8 ounces. A high birth weight means that the baby is more than 8 pounds, 13 ounces.

What can cause low birth weight?

A baby with a low birth weight can be born too small, too early (premature), or both. This can happen for many different reasons. They include:

What problems can low birth weight cause?

Babies with low birth weight may be more at risk of certain health problems. They include immediate problems, such as:

There is also a higher risk of longer-term problems, including:

What can cause high birth weight?

Causes of high birth weight can include:

What problems can high birth weight cause?

High birth weight can be a concern because it can make delivery of the baby difficult and raise the risk of birth injuries. The baby is at higher risk of problems with:

Can birth weight problems be prevented?

You may be able to prevent some birth weight problems by:

  • Getting regular checkups during pregnancy
  • Getting the right amount of nutrition and calories during pregnancy
  • Controlling your blood sugar if you have diabetes
  • Avoiding substance use during pregnancy

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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.