Low birth weight is defined as a birth weight of an infant lower than 2.5 kg. Normally, a newborn baby should have a body weight between 2.5 kg and 4.2 kg.
Low birth weight can be caused by several factors.
One factor is preterm birth, which means the baby is born before 37 weeks of pregnancy. It is also possible that the infant is small for the gestational age.
Mothers who are pregnant at young ages, have multiple babies, poor diet, heart disease, hypertension, alcohol abuse, and poor prenatal care may have preterm birth.
In addition, environment can cause low birth weight. Mothers who smoke (including second-hand smoking) during pregnancy are more likely to give birth to low-birth weight infants.
Toxins in the environment, such as lead, may lead to miscarriage, preterm birth and low birth weight. Very loud noises, like airplane noise may have bad influence on fetal growth and cause low birth weight.
Low birth weight is linked to delayed growth and cognitive development and chronic disease later in life. Babies with low birth weight may have higher risk of death and disability.
In a recent study, Sweden researchers found that providing low-birth weight babies with iron supplement could improve their neurological development and reduce behavioral problems at school age.
The findings are published in the journal Pediatric Research.
In the study, researchers examined 285 late preterm and term babies whose weight were between 2kg and 2.5 kg. These babies were defined as being marginally low birth weight.
Half of them received iron supplements while the other half did not. All babies were tracked from 6 weeks of age to 6 months of age.
The results showed that babies who received iron supplement had less chance of iron deficiency and anemia when they were 6 months old.
Furthermore, when tested again at 3.5 years old, these babies showed fewer behavioral problems.
Among all the babies, 207 were tested again at 7 years old. The researchers found that although no IQ difference was found between the iron group and the non-iron group, the iron group showed less aggressive and rule-breaking behaviors.
These children also had less thought problems that could predict autism spectrum disorders.
These findings show that receiving iron supplements may help reduce symptoms of subclinical neurodevelopmental issues.
The researchers suggest that iron supplement can have long lasting benefits on babies with low birth weight. Therefore, all low birth weight children, including those marginally low birth weight, should have iron supplements after birth.