Eating disorders are believed to be caused by a complex interaction of genetic and environmental factors, according to background information in the article. Observational reports suggest that problems during neurodevelopment in the fetus might lead to anorexia nervosa or bulimia nervosa later in life, and some studies have found a correlation between obstetric complications and anorexia nervosa. "Obstetric complications might have more than one role in the etiopathogenesis of eating disorders; first, they may cause hypoxic-induced damage to the brain that impairs the neurodevelopment of the fetus, and second, the adequacy of nutrition during pregnancy and in the immediate postnatal period seems to influence the nutritional status of the adult and appetite programming throughout life," the authors write.
Angela Favaro, M.D., Ph.D., and colleagues at the University of Padua, Italy, completed an analysis of 114 females with anorexia nervosa, 73 with bulimia nervosa and a control group of 554 without either condition, all born at Padua Hospital between Jan. 17, 1971, and Dec. 30, 1979. Fifteen of the people with anorexia, 22 with bulimia and all of the control subjects had participated in a previous study of the prevalence of eating disorders in Padua. The authors added in a sample of 99 people with anorexia and 51 with bulimia who had been referred to an outpatient clinic for their conditions. They then merged the samples and analyzed data about obstetric complications obtained from hospital archives.
Several specific complications in the mother--including maternal anemia (low levels of hemoglobin in the blood), diabetes mellitus and placental infarction (death of part of the tissue of the placenta)--increased a child's risk of developing anorexia nervosa. Neonatal heart problems, hypothermia (low body temperature), tremors and hyporeactivity (a less than normal response to stimuli) also were associated with later development of anorexia. Placental infarction, neonatal hyporeactivity, early difficulties with eating, shorter than average birth length and low birth weight were associated with bulimia nervosa.
In addition, the number of complications affected the age at which the children developed anorexia nervosa. Those with more than five complications developed the disorder at an average age of 16.3, compared with 17.5 years for those with one to five complications and 18.8 years for those with no complications. "This type of relationship is considered evidence of a causal link and would indicate that an impairment in neurodevelopment could be implicated in the pathogenesis of anorexia nervosa," the authors write.
"These findings seem to show some resemblance to what has been found in schizophrenia and, with less evidence, in other severe psychiatric disorders," they report--that some obstetric complications may contribute to the development of psychiatric illnesses by robbing a fetus of the oxygen and nutrients needed for proper neurodevelopment or by causing neonatal brain damage. "However, this observation should lead to a search for other more specific risk factors that interact with perinatal factors and are able to predict the development of one particular psychiatric disorder rather than another."
In addition, they write, future research "should try to assess the prognostic impact of the presence of obstetric complications and whether this factor might help in the choice of appropriate and effective treatment."
(Arch Gen Psychiatry. 2006;63:82-88. Available pre-embargo to the media at www.jamamedia.org.)
Editor's Note: This study was supported by the University of Padua, Padua, Italy.
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