The risk of developing endometriosis is higher if the mother has the condition, or if she smokes during pregnancy or child-rearing, while the odds are lower for those that have been breastfed, a study suggests.
This study was discussed recently at the American Society for Reproductive Medicine (ASRM) 75th Annual Scientific Congress and Expo, in a presentation titled, “In Utero and Early Life Exposures in Relation to Odds of Endometriosis in Adolescents and Young Adults.”
The results stem from an analysis of data from The Women’s Health Study: From Adolescence to Adulthood (A2A, NCT01738204). It was launched in 2012 to explore health topics that affect women over their lifetime and it is sponsored by the Boston Center for Endometriosis and run by the Brigham and Women’s Hospital and the Boston Children’s Hospital.
From 2012 to 2018, the database containing anonymous patient information was built and participants’ biological samples, such as blood, cells, and tissues, were collected and stored for further research.
In this analysis, researchers identified 295 patients from the database — between the ages of 7 and 24 years — with confirmed endometriosis. Almost all cases (95%) were diagnosed as rASRM stage 1 (minimal) or stage 2 (mild).
As a comparison, 309 age-matched subjects without endometriosis were selected from the database as controls.
All participants completed the World Endometriosis Research Foundation (WERF) Endometriosis Phenome and Biobanking Harmonisation Project (EPHect) questionnaire.
Participant information from before birth and early life was collected, such as mother’s age when they were born, their birth weight, length of pregnancy, if the participant had been breastfed, and whether the parents smoked during their pregnancy and/or during infancy and childhood.
The analysis revealed that, in people with endometriosis, 50% of their mothers also had the condition compared to only 9% of the control group.
Breastfed participants had lower odds — less than half — of being diagnosed with endometriosis than those who were not breastfed.
Despite the small numbers affected, those with mothers that smoked during pregnancy were four times more likely to be diagnosed with endometriosis. If their mother smoked during infancy to childhood, the odds of diagnosis were 2.5 times higher.
Preterm birth and low birth weight were not associated with endometriosis diagnosis risk.
“Further exploration and replication are necessary to draw conclusions regarding risk among those diagnosed during adolescence compared to those diagnosed during adulthood,” the authors concluded. “As these exposures are potentially modifiable, solidifying these associations will form the basis of informative public health messages to prevent endometriosis.”
In in a press release, Hugh Taylor, MD, ASRM vice president, expressed support of the research: “Research like this into potential causes of endometriosis is extremely valuable. Identifying modifiable risk factors, like parental smoking, and taking action on them can help reduce the impact of this painful and debilitating condition,”