Prematurity, Birth Trauma Linked To Risk of Anorexia Nervosa

A small number of cases of anorexia nervosa can be traced back to birth trauma or very preterm births, according to Swedish researchers (Arch Gen Psychiatry 1999;56:634). Subtle brain injuries from premature birth or birth trauma may later pair with individual or environmental factors and interfere with an individual’s ability to differentiate hunger and satiety.

In a population-based case-control study of all girls born in Sweden from 1973 to 1984, Sven Cnattingius, MD, PhD, and colleagues at the Karolinska Institute identified 781 girls who had been discharged from any hospital in Sweden with a primary diagnosis of anorexia nervosa between the ages of 10 and 21 years.

Greater risk before 32 weeks gestation

The risk of developing anorexia nervosa was increased for infants with a cephalhematoma (usually caused by vaginal instrumental delivery) and for those born before 32 gestational weeks. The girls who had very preterm births and were small for gestational age had a greater risk of developing AN than girls with higher birth weights for gestational age.

Why does AN develop in such circumstances?

The authors theorize that prematurity leads to suboptimal neurologic development and cognitive delay, which might influence behavioral problems, including severe eating difficulties. According to the researchers, such difficulties usually start early and continue throughout childhood. Early eating disorders may then persist throughout adolescence, and such problems often precede the onset of anorexia nervosa. In addition, very preterm birth may cause early hypothalamic dysfunction.