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Birth Weight

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:

  • Health problems in the pregnant parent
  • Taking certain medicines during pregnancy
  • Substance use during pregnancy
  • Infections during pregnancy
  • Being pregnant with multiple babies
  • Problems with the placenta, the organ that brings oxygen and nutrients to the baby
  • Having small parents
  • Genetic conditions in the baby
  • Birth defects
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:

  • Breathing problems
  • Infections
  • Hypoglycemia (low blood sugar)
  • Jaundice
  • Trouble keeping warm

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

  • Delayed motor and social development
  • Learning disabilities
  • Certain health conditions as an adult, such as heart disease, high blood pressure, diabetes, and obesity
What can cause high birth weight?

Causes of high birth weight can include:

  • Having big parents
  • Diabetes in the pregnant parent
  • Certain genetic conditions
  • Too much weight gain during pregnancy
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:

  • Blood sugar
  • Breathing problems
  • Jaundice
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