(P19-016-23) Risk of Iron Deficiency in Women With Endometriosis: A Population-Based Prospective Cohort Study

Objectives: To examine the association between endometriosis and the risk of iron deficiency in a prospective longitudinal study.

Methods: This study included 3294 women born in 1973-78 using data from the Australian Longitudinal Study on Women’s Health followed-up from 2000 to 2018. Women with endometriosis were identified using self-reported longitudinal surveys linked to administrative health records. At each survey, women were also asked to report the diagnosis of iron deficiency with or without anemia. Generalized estimating equations for binary responses with an autoregressive correlation matrix were used to examine the association between endometriosis and the risk of iron deficiency over the seven-time points.

Results: We found that women with endometriosis had a significantly higher risk of iron deficiency than those without endometriosis after adjusting for socio-demographic, lifestyle, reproductive, and nutrition factors, adjusted OR (95% CI), 1.46 (1.29, 1.66), p < 0.0001. Women with a surgically confirmed diagnosis and those with clinically suspected endometriosis had an increased risk of iron deficiency, 1.38 (1.17, 1.64) and 1.53 (1.30, 1.81), respectively. These associations, however, were slightly attenuated (by 8%) when adjusted for the presence of heavy menstrual bleeding.

Conclusions: This study suggests that women with endometriosis are at a higher risk of developing iron deficiency than those without endometriosis. A further study could explore the causal pathways between endometriosis and iron deficiency.

Funding Sources: Australian Longitudinal Study on Women’s Health is funded by the Australian Government Department of Health.
Gita Mishra holds the Australian National Health and Medical Research Council Leadership Fellow APP2009577.