Relative weight at ages 10 and 16 years and risk of endometriosis: a case-control analysis

BACKGROUND: Although previous epidemiological studies have shown that women with endometriosis are more likely to be thinner and underweight, it is currently not clear whether this is a true characteristic of women who develop endometriosis or a consequence of their disease and its symptoms. The aim of this study was to investigate the relationship between endometriosis and relative weight in childhood and adolescence, prior to diagnosis. METHODS: This case-control study included 268 Australian women with surgically confirmed moderate to severe endometriosis (cases) and 244 women without endometriosis (controls). Relative weight at ages 10 and 16 years, as recalled and classified ('underweight', 'average weight' and 'overweight') separately by the women themselves and their mothers, was analyzed. RESULTS: Women who reported being overweight at 10 years had an increased risk of endometriosis (OR 2.8; 95% CI 1.1-7.5). Mothers' reports and concordant responses among mother-daughter pairs were consistent with this association. There was no clear evidence of an association between relative weight at 16 years and risk of endometriosis. CONCLUSIONS: These data suggest that being overweight during late childhood is associated with the development of endometriosis; however, the results warrant confirmation in larger study populations.