The risk of developing food allergy in premature or low birth-weight children.

Researchers know that children born pre-maturely or children born very small, have an immature immune system and immature digestive system.  Despite this, their immune system is able to respond to some things “normally”, for example, vaccines.  Researchers have many questions about how pre-mature and low birth weight infants respond when exposed to food allergens. 

Some researchers have assumed that children born with immature immune and digestive systems are more prone to developing food allergies.

Our Research Question:  Are children born pre-maturely or born with low birth weight more at risk of developing food allergies compared to normal-birth-weight children?

SAGE researchers looked at the health records of all children born in Manitoba in 1995.  Children were divided into groups based on * gestational age and * weight at birth.

Researchers then looked at the number of children in each group that had food allergies. Children who had had a hospital or emergency room admission for food allergy or a prescription for an Epinephrine auto-injector (Epipen or Twinject) before the age of 7 were considered food allergic.

*Gestational age refers to how far along the mother was in her pregnancy at the time of birth (30 weeks, 35 weeks, 40 weeks).  Children born at 37 weeks or less were considered pre-mature.

* Low birth weight refers to children who weigh less than 2500 grams at birth

Findings:

Almost 14 000 children were born in Manitoba in 1995. 

6.3% were born prematurely

4.9 % were born with a low birth weight 

2.06% of the premature/low birth weight children had food allergy by the time they were 7 years old.

The rate of food allergy in the premature/low birth weight group was the same as the rate of food allergy in normal children.

Many doctors have suggested to parents of pre-mature and low birth weigh babies not feed them solids before 6 months of age, milk or eggs before 1 year and peanuts and fish before age 3, believing that this would help prevent the development of food allergies. 

In this study, pre-mature children who ate these food before the recommended age did not have a higher rate of food allergy.

Risk factors for developing food allergy were: having a mother with asthma or food allergies, having a higher income and being a boy.

Conclusion:

Pre-maturity and low birth weight did not increase a child’s risk of developing food allergy. 

Delaying certain foods until a certain age did not decrease the risk of  developing food allergy. More research needs to be done to see if delaying certain foods until later in life increases or decreases the risk of food allergy.

The risk of developing food allergy in premature or low birth-weight children.

Liem JJ, Kozyrskyj AL, Huq SI, Becker AB. J Allergy Clin Immunol. 2007 May;119(5):1203-9. Epub 2007 Mar 26