Low Birth Weight

In the U.S., the average newborn weighs approximately 8 pounds. If a baby is less than 5 pounds, 8 ounces at birth, however, that baby is considered low birth weight. Babies weighing even less when born—3 pounds, 5 ounces—are described as being very low birth weight. More than 8 percent of babies born in the U.S. are low birth weight, and this number continues to increase. Many babies with low birth weight are also premature, although not all.

A baby with low birth weight will not be as strong as a full-term baby, and the lower the birth weight, the greater the risk for complications. Nearly all low birth weight babies need specialized care in a hospital’s Neonatal Intensive Care Unit (NICU) until they gain weight and are well enough to go home. Problems associated with low birth weight include:

  • Breathing problems, such as infant respiratory distress syndrome
  • Inability to maintain body temperature
  • Difficulty feeding and gaining weight
  • Neurologic problems
  • Infections
  • Gastrointestinal problems
  • Sudden Infant Death Syndrome (SIDS)

Women most at risk for having a low birth weight baby include

  • African-Americans
  • Teens, especially those under age 15
  • Women having twins, triplets or more babies (more than 50 percent of multiple birth babies have low birthweight)
  • Smokers, or women who use or abuse drugs or alcohol during pregnancy

Additionally, some women develop a condition called intrauterine growth restriction (IUGR). IUGR means there are issues with the placenta, the women’s health or the baby's condition and which affects growth of the fetus.

Other risk factors that can contribute to low birth weight include:

  • Dealing with health ongoing health conditions, such as diabetes or high blood pressure
  • Getting pregnant too soon after having a baby
  • Being underweight before or during pregnancy
  • Getting late or no health care during pregnancy
  • Vaginal bleeding in your second or third trimester
  • Having a sexually transmitted disease (STD) or urinary tract infection (UTI)
  • Premature rupture of the membranes
  • Being pregnant due to in vitro fertilization (IVF)
  • Being pregnant with a baby who has a birth defects
  • Having a family history of premature birth
  • Exposure to a hormone known as DES

Reducing Risk of Low Birth Weight
Many times, there is nothing you can do to prevent low birth weight, such as if you are pregnant with twins or triplets. However, sometimes there are lifestyle behaviors you can modify that can help reduce your risk such as:

  • Quit smoking
  • Stop use of alcohol and drugs
  • Reduce stress
  • Avoid standing for many hours at a time
  • Avoid pollutants

A gynecologist can help you stay healthy through your pregnancy so you are less likely to give birth to a low weight baby. Also, because your nutrition and weight so closely affects the weight of your fetus, eating a healthy diet and gaining the proper amount of weight in pregnancy are essential.