Association between early-life environmental exposures and risk of endometriosis in the Constances cohort
Résumé
BACKGROUND AND AIM[|]The etiology of endometriosis is not well understood; few risk factors are established and knowledge on environmental influences on endometriosis is limited. This study aimed to investigate the associations between various environmental exposures during the perinatal and childhood periods and the risk of endometriosis in women.[¤]METHOD[|]Constances is a prospective cohort study involving 220,000 French adults (of whom 116,000 are women) aged 18-69 years at inclusion between 2012 and 2020. Participants are regularly followed-up through detailed health, environmental, and behavioral questionnaires. The analysis included 108,581 women with health and exposure data available. Associations with self-reported endometriosis were investigated using multivariable logistic regression models, adjusted for potential confounders identified through direct acyclic graphs.[¤]RESULTS[|]Low birth weight and low body mass index (BMI) at birth were associated with higher odds of endometriosis (birth weight <2500g: adjusted odds-ratio (aOR)=1.48, 95% confidence interval (CI)=1.01-2.17, vs. 2500g-3500g; WHO BMI ≤3rd percentile: 1.40, 95% CI=1.02-1.91, vs. 3-97th percentile). Conversely, exposure to breastmilk for at least 6 months and having farmer parents were inversely associated with endometriosis odds (aOR=0.54, 95% CI=0.34-0.88 and aOR=0.78, 95% CI=0.67-0.91, respectively). We also found associations with the geographical origin of the participants (French overseas territories: aOR=1.52, 95% CI=1.14-2.04; North Africa: aOR=0.70, 95% CI=0.52-0.94; vs. Mainland France). However, being born by Cesarean section, birth length, prematurity, number of siblings, or body shape during infancy or adolescence were not associated with endometriosis.[¤]CONCLUSIONS[|]Our findings from this large population-based cohort in France suggest associations between several perinatal and childhood exposures and endometriosis. Additional research is required to further elucidate the influence of the early-life and childhood environments on endometriosis. These findings could carry significant implications for the primary prevention of the disease. No conflict of interest.[¤]