Low birth weight is most often caused by being born too early (premature birth). That means before 37 weeks of pregnancy. A premature baby has less time in the mother's womb (uterus) to grow and gain weight. Much of a baby's weight is gained during the last weeks of pregnancy.
Another cause of low birth weight is a condition called intrauterine growth restriction (IUGR). This occurs when a baby does not grow well during pregnancy. It may be because of problems with the placenta, the mother's health, or the baby's health. Babies can have IUGR and be:
Your healthcare provider may also use fetal ultrasound to check your baby's growth and development. Ultrasound uses sound waves to create a picture of your fetus. It is a more accurate than checking fundal height. Measurements can be taken of your baby's head, belly (abdomen), and upper leg bone (femur). These measurements are used to estimate his or her weight.
Babies are weighed within the first few hours after birth. The weight is compared against the number of weeks of pregnancy (gestational age). If your baby weighs less than 2,500 grams (5 pounds, 8 ounces), he or she has a low birth weight. Babies weighing less than 1,500 grams (3 pounds, 5 ounces) at birth are considered very low birth weight. Babies who weigh less than 1,000 grams (2 pounds, 3 ounces) are extremely low birth weight.
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.
Treatment for low birth weight often includes:
How well a baby with low birth weight does depends largely on how much the baby weighs at birth. Babies who weigh less than 1 pound, 1.5 ounces (500 grams) have the most problems and are much less likely to survive.
Low-birth-weight babies typically "catch up" in physical growth if they have no other complications. Babies may need to have special follow-up healthcare programs.
Low-birth-weight babies often have problems. The baby's tiny body is not as strong as a baby of normal birth weight. He or she may have a harder time eating, gaining weight, and fighting infection. Low-birth-weight babies often have a hard time staying warm because they don't have much fat on their bodies.
Babies that are born premature often have complications. It is sometimes hard to tell if the problems are because they were born early, or because they are so small. In general, the lower the birth weight, the greater the risk for complications. The following are some of the common problems of low-birth-weight babies:
Babies with very low birth weight are at risk for long-term complications and disability. Long-term complications may include:
Talk with your baby's healthcare provider for information about your baby's risks for complications.
More babies are surviving even though they are born early and are very small. This is because of advances in the care of sick and premature babies. But preventing preterm births is one of the best ways to prevent babies born with low birth weight.
Regular prenatal care is the best way to prevent preterm births and low-birth-weight babies. At prenatal visits, the healthcare provider will check the health of you and your fetus. It is important to:
Tips to help you get the most from a visit to your child’s healthcare provider:
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