Low Birth Weight
The term low birth weight traditionally was defined as a birth weight under 2500 grams, or 5 lbs. 8 oz. It was discovered that some of these babies were premature, some had suffered from intrauterine growth restriction, and some were constitutionally small (just small persons who are normal otherwise).
Over time, the term has changed to mean a birth weight less than the tenth percentile for gestational age, which happens to be around 2500 grams for a term baby. Low birth weight is a concern because of the potential health risks to the baby.
Understanding Low Birth Weight
Babies that have low birth weight may be the result of preterm birth or intrauterine growth restriction, where they simply do not grow as large as they should due to problems with the placenta, birth defects, or problems with the mother's health. They also may just be small persons or constitutionally small.
Distinguishing between these possibilities prenatally requires a great deal of skill and experience. Babies who are low birth weight due to prematurity or growth restriction are more likely to have problems as a newborn, including breathing problems, and to experience disabilities.
Signs of preterm labor include contractions every 10 minutes, backache, bloody show, increased vaginal discharge, leaking fluid or blood, pelvic pressure, period-like cramps, and abdominal cramps. If you experience any of these, contact your health-care provider immediately.
Risks for Low Birth Weight
One in 13 babies is born with low birth weight. Women over 35 are 20 to 40 percent more likely than younger women to have a low birth-weight baby, generally due either to prematurity or intrauterine growth restriction. Multiples are at a high risk of having low birth weight. African American babies have two times the rate of low birth weights as other babies.
Treatment for Low Birth Weight
Low birth weight can be predicted during pregnancy using ultrasound and fundal height (a measurement of the size of the uterus). If you are told your baby appears small, your health-care provider may encourage you to rest more often, avoid stress and strenuous exercise, and make sure you are taking in enough calories. Low birth-weight babies may need specialized care in a neonatal intensive care unit (NICU), where they are placed in heated beds, given feeding tubes, and monitored for breathing difficulties.
