Low Birthweight in Newborns | Boston Children's Hospital (2024)

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Low Birthweight in Newborns | Boston Children's Hospital? ›

A birthweight less than 5 pounds, 8 ounces, is diagnosed as low birthweight. Babies weighing less than 3 pounds, 5 ounces, at birth are considered very low birthweight. The average newborn weighs about 7.6 pounds, and about 7.6 percent of all newborns in the U.S. have low birthweight.

Low birth weight is a term used to describe babies who are born weighing less than 5 pounds, 8 ounces (2,500 grams). An average newborn usually weighs about 8 pounds. 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.

Which babies need special care? Most babies admitted to the NICU are preterm (born before 37 weeks of pregnancy), have low birth weight (less than 5.5 pounds), or have a health condition that needs special care.

If your baby weighs less than 2,500 g (5 pounds, 8 ounces), they have a low birth weight. Babies weighing less than 1,500 g (3 pounds, 5 ounces) at birth are considered very low birth weight. Babies who weigh less than 1,000 g (2 pounds, 3 ounces) are extremely low birth weight.

Preterm babies stay in the NICU until their organs develop enough to stay alive without medical support. Some babies need NICU care for weeks or months until they can breathe on their own, eat by mouth and maintain their body temperature and body weight.

Nearly all low birthweight babies need specialized care in the Neonatal Intensive Care Unit (NICU) until they gain weight and are well enough to go home. Fortunately, there is a 95 percent chance of survival for babies weighing between 3 pounds, 5 ounces, and 5 pounds, 8 ounces.

Some babies with low birthweight are healthy, even though they're small. But having a low weight at birth can cause serious health problems for some babies. A baby who is very small at birth may have trouble eating, gaining weight and fighting off infections. Some may have long-term health problems, too.

Babies born before 34 weeks go to the Neonatal Intensive Care Unit (NICU). Babies born between 34 and 37 weeks who weigh more than 1,800 grams (about 4 pounds) may be able to go to the Progressive Care Nursery (PCN).

A premature baby needs to be able to maintain their body temperature in an open crib before they can go home. 1 When your baby is able to do this will depend more on their weight than their gestational age. In general, preemies can maintain their own body temperature once they weigh about 4 pounds.

In general, our babies would need to weigh at least 2000 grams (about 4 1/2 lbs), in addition to other requirements, to go home. Occasionally, a baby would go home weighing less than that, if it was SGA (small for gestational age), which means that it was more mature than what its size would indicate.

Which disorder is commonly associated with very low birthweight babies? ›

This is called fetal growth restriction (FGR). In the past, this was called intrauterine growth restriction. It may happen because of problems with the placenta, the pregnant person's health, or birth defects. Most very low birth weight babies who have FGR are also born early.

The primary cause of low birthweight is premature birth (being born before 37 weeks gestation). Being born early means a baby has less time in the mother's uterus to grow and gain weight.

Having a low birth weight doesn't mean your child will be below average in weight when they grow up. In fact, some infants with a low birth weight are healthy even though they're small. But your baby's birth weight can help their providers determine if they need extra attention immediately following birth.

“There are different levels of delays and long-term effects,” Dr. Reid adds, “but the vast majority of babies born at 28 to 30 weeks and beyond can survive without significant complications. At less than 28 weeks, survival is possible, but the risk of long-term complications is much higher.”

Estimated probabilities (95% confidence intervals) of 180 days survival were 0.632 (0.5831–0.677) for infants with a birth weight of 250–499 g, 0.817 (0.799-0.834) for 500–749 g, 0.931 (0.920–0.940) for 750–999 g, 0.973 (0.967–0.979) for 1,000–1,249 g, and 0.985 (0.981–0.988) for 1,250–1,499 g, respectively (Figure 1).

What Is the NICU? When babies are born early, have health problems, or a difficult birth they go to the hospital's NICU. NICU stands for "neonatal intensive care unit." There, babies get around-the-clock care from a team of experts.

A birthweight less than 2,500 grams (5 pounds, 8 ounces) is diagnosed as low birthweight. Babies weighing less than 1,500 grams (3 pounds, 5 ounces) at birth are considered very low birthweight.

Low birthweight is defined as less than 2,500 grams (up to and including 2,499 grams).

Low birth weight has been defined by WHO as weight at birth of < 2500 grams (5.5 pounds). What are the consequences and implications? Low birth weight is caused by intrauterine growth restriction, prematurity or both.

These babies have a birth weight below the 10th percentile. This means they are smaller than 90% of (most) other babies of the same gestational age. Most babies weigh more than 5 pounds, 13 ounces by the 37th week of pregnancy. Babies born weighing less than 5 pounds, 8 ounces are considered low birth weight.