Pregnancy Triggers Binge Eating in Some

Sept. 7, 2007 – Many women with eating disorders go into remission while pregnant, but pregnancy appears to trigger one type of eating disorder in some, new research shows.

In one of the first large, long-term studies to examine eating disorders in pregnancy, researchers from the University of North Carolina, Chapel Hill and the University of Oslo, Norway discovered some pregnant women are more vulnerable to binge eating disorder.

Binge eating disorder is characterized by repeated episodes of binge eating and feelings of shame or disgust by the behavior. But sufferers do not purge.

The study included roughly 41,000 women in Norway followed from their 18th week of pregnancy.

While 39% of the women with binge eating disorder stopped bingeing during pregnancy, 711 new cases of the disorder were also reported.

Lower-income and poorly educated women seemed to be particularly vulnerable to developing the disorder during pregnancy, according to Cynthia Bulik, PhD, who led the study team.

The long-time eating disorder researcher tells WebMD that there is good news and bad in the findings.

"Pregnancy appears to be a window of remission for some women, but it is also a window of risk for others," Bulik says.

Eating Disorders and Pregnancy

The ongoing trial will eventually follow 100,000 women in an effort to shed light on the impact of eating disorders on pregnant women and their babies.

Relying on self-reported surveys, the University of North Carolina researchers explored rates of remission, continued disordered eating, and new cases of eating disorders among the 41,000 women who have been enrolled in the study.

Specifically, the women were asked about four subtypes of eating disorders: anorexia nervosa, bulimia, binge eating disorder (binge eating at least weekly), and a disorder characterized by purging without bingeing (purging at least weekly).

Binge eating was the most commonly reported eating disorder. In the study, 1,405 women (3.5%) acknowledged engaging in the behavior before pregnancy, 1,856 (4.8%) acknowledged bingeing during pregnancy, and 779 (2%) acknowledged bingeing both before and during pregnancy.

Of women who reported having bulimia with purging or binge eating disorder before pregnancy, 40% and 39%, respectively, said they did not binge -- or binge and purge -- during pregnancy.

Only 37 (0.1%) women reported being anorexic before pregnancy, and it was not clear from the study how this disorder manifested during pregnancy and beyond.

Of the four eating disorders examined, binge eating disorder was the only one associated with a significant number of new cases occurring during pregnancy.

The fact that low socioeconomic status was a risk factor for developing the disorder during pregnancy points to psychological and social stresses playing a role, Bulik says.

The study appears in the August issue of the journal Psychological Medicine.

"It's possible that the combination of biology and high stress may make pregnancy a biological trigger of the disorder," she says.