In utero exposures and endometriosis: the Endometriosis, Natural History, Disease, Outcome (ENDO) Study

In utero exposures were not associated with a visualized endometriosis diagnosis in either an operative or population cohort of women in contrast to earlier evidence.


Erin Foran Wolff, M.D., Liping Sun, M.S., M.D., Mary L. Hediger, Ph.D., Rajeshwari Sundaram, Ph.D., C. Matthew Peterson, M.D., Zhen Chen, Ph.D., Germaine M. Buck Louis, Ph.D.

Volume 99, Issue 3, Pages 790-795, 1 March 2013



To assess in utero exposures and the odds of an endometriosis diagnosis.


Matched cohort design.


Fourteen participating clinical centers in geographically defined areas in Utah and California.

Study cohorts:

The operative cohort comprised 473 women undergoing laparoscopy/ laparotomy, and was matched on age and residence to a population cohort comprising 127 women undergoing pelvic magnetic resonance imaging (MRI), 2007-2009.



Main outcome measures:

Women completed standardized interviews prior to surgery or MRI regarding in utero exposures: mothers’ lifestyle during the index pregnancy, and the index woman’s gestation and birth size. Endometriosis was defined as visually confirmed disease in the operative cohort, and MRI visualized disease in the population cohort. The odds of an endometriosis diagnosis and corresponding 95% confidence intervals (AOR; 95% CI) were estimated for each exposure by cohort using logistic regression and adjusting for current smoking, age at menarche, body mass index, and study site.


Endometriosis was diagnosed in 41% and 11% of women in the operative and population cohorts, respectively. In the primary analysis, AORs were elevated for maternal vitamin usage (1.27; 95% CI =0.85-1.91), maternal cigarette smoking (1.16; 95% CI=0.61-2.24), and low birth weight (1.1; 95% CI=0.92-1.32). Reduced odds were observed for maternal usage of caffeine (0.99; 95% CI=0.64- 1.54), alcohol (0.82; 95% CI=0.35-1.94), paternal cigarette smoking (0.72; 95% CI=0.43-1.19) and preterm delivery (0.98; 95% CI=0.47-2.03). Sensitivity analyses mostly upheld the primary results except for a decreased AOR for preterm birth (0.41; 95% CI=0.18-0.94) when restricting to visualized and histologically-confirmed endometriosis in the operative cohort.


In utero exposures were not significantly associated with the odds of an endometriosis diagnosis in either cohort.

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