What is low birth weight?
Low birth weight is a term used to describe babies who are born weighing less than 2,500 grams. An average newborn usually weighs about 3,700 grams. A low-birth-weight baby may be healthy even though he or she is small. But a low-birth-weight baby can also have many serious health problems.
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:
- Low oxygen levels at birth
- Trouble staying warm
- Trouble feeding and gaining weight
- Breathing problems and immature lungs (infant respiratory distress syndrome)
- Nervous system problems, such as bleeding inside the brain (intraventricular hemorrhage)
- Digestive problems, such as serious inflammation of the intestines (necrotizing enterocolitis)
- Sudden infant death syndrome (SIDS)
Babies with very low birth weight are at risk for long-term complications and disability. Long-term complications may include:
- Cerebral palsy
- Developmental delay
How common is low birth weight?
Low birth weight is common. It’s more prevalent in developing countries. Please discuss with your doctor for further information.
What are the symptoms of low birth weight?
In addition to weighing less than 2,500 grams, babies with low birth weight look much smaller than babies of normal birth weight. A low-birth-weight baby’s head may look bigger than the rest of his or her body. He or she often looks thin with little body fat.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If your baby has any signs or symptoms listed above or if you have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes low birth weight?
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:
- Full term. That means born from 37 to 41 weeks of pregnancy. These babies may be physically mature, but small.
- These babies are both very small and physically immature.
What increases my risk for low birth weight?
There are many risk factors for low birth weight, such as:
- Infection during pregnancy
- Not gaining enough weight during pregnancy
- Previous pregnancy with a low-birth-weight baby
- Alcohol or drug use
- Age less than 17 or more than 35 years
- African-American background
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is low birth weight diagnosed?
One of the main reasons for regular prenatal exams is to make sure your baby is growing well. During pregnancy, the size of your fetus is estimated in different ways. Your steady weight gain is one way of checking on fetal growth. Another way is fundal height:
- To check fundal height, your healthcare provider measures from the top of your pubic bone to the top of your uterus (fundus).
- Fundal height is measured in centimeters (cm). It is about the same as the number of weeks of pregnancy after the 20th week. For example, at 24 weeks’ gestation, your fundal height should be close to 24 cm.
- If the fundal height is less than expected, it may mean the baby is not growing well.
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, he or she has a low birth weight. Babies weighing less than 1,500 grams at birth are considered very low birth weight. Babies who weigh less than 1,000 grams are extremely low birth weight.
How is low birth weight treated?
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:
- Care in the neonatal intensive care unit (NICU)
- Temperature-controlled bed
- Special feedings. Sometimes these are given through a tube into the stomach if a baby cannot suck. Or they are given through an IV (intravenous) line.
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.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage low birth weight?
According to the World Health Organization, babies with LBW should be fed with their mother’s breast milk whenever possible. Breastmilk (and breastfeeding if possible) can help promote growth and weight gain. If their birth mother’s breast milk isn’t available, human donor milk may be used. Formula should be considered as a last resort for nutrition.
Prevention of preterm births is one of the best ways to prevent babies born with low birthweight. Prenatal care is a key factor in preventing preterm births and low birthweight babies.
At prenatal visits, the health of both mother and fetus can be checked. Because maternal nutrition and weight gain are linked with fetal weight gain and birthweight, eating a healthy diet and gaining the proper amount of weight in pregnancy are essential. Mothers should avoid alcohol, cigarettes and illicit drugs, which can contribute to poor fetal growth, among other complications.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: February 21, 2019 | Last Modified: February 21, 2019
What Causes Low Birth Weights? https://www.healthline.com/symptom/low-birth-weights. Accessed February 21, 2019.
Low Birthweight in Newborns | Symptoms and Causes. http://www.childrenshospital.org/conditions-and-treatments/conditions/l/low-birthweight-in-newborns/symptoms-and-causes. Accessed February 21, 2019.
Low Birth Weight. https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=90&contentid=p02382. Accessed February 21, 2019.