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Newborn and Infant Care

Low birthweight newborns



Why are low birthweight babies at risk? What are the most common complications that accompany low birthweight newborns?


Low birthweight babies are babies born at less than 1500 grams. Low birth weight can be caused by either being born prematurely or by being severely growth-restricted in utero.

The most common cause of low birth weight (LBW)is prematurity. The normal pregnancy is from 38 to 42 weeks. If a baby is born prior to 38 weeks gestation, he/she is preterm or premature.

You are correct that LBW babies are at greater risk than full-term babies. The primary reason is of course, that their organs and organ systems are not as fully developed as a full-term babies; this leads to significant problems that they must overcome to make a successful transition to extrauterine life.

The lack of maturity predisposes LBW babies to some common problems: respiratory distress syndrome (due to lung immaturity), patent ductal arteriosus (PDA, secondary to heart immaturity), infection (due to immature and inexperienced immune system), hyperbilirubinemia (due to immature liver function), and feeding difficulties (due to immature GI function)for example.

The last trimester of pregnancy is a very important part of the growth and development of the fetus. During this time, the fetus receives antibodies from the mother that can help prevent or fight infection and also receives sufficient stores of body fat and water to sustain the baby until the mother`s milk supply comes in. Also the lungs mature and begin to increase the production of surfactant, a phospholipid that helps keep the babies lungs from being stiff and collapsing after each breath.

Despite the difficulties caused by being premature, many LBW babies can survive the problems and do well. Specially-equipped neonatal intensive care units, staffed with neonatologists and neonatal intensive care nurses provide the necessary care to help these "born too soon" babies.

If you have specific questions, I`d be happy to answer them.

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Response by:

Judy Wright Lott, RNC, NNP, DSN
Associate Professor of Nursing
College of Nursing
University of Cincinnati