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A new study from Karolinska Institutet involving over a million women links difficult childhood experiences to the risk of being diagnosed with endometriosis later in life. The study shows a link between childhood exposure to violence and a two-fold increase in the risk of developing this gynecological disease.

Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus. These cells attach to the abdominal lining, uterus, ovaries or other organs and form endometriosis lesions. The lesions react to sex hormones and bleed during menstruation, leading to pain and inflammation that can cause adhesions between organs, which increases the pain.

Although endometriosis, which affects one in 10 women, is a relatively common disease, its causes are still not fully understood.

A study published in the journal Human Reproduction has now identified a link between different types of difficult childhood experiences and an increased risk of developing endometriosis.

The study included more than 1.3 million women born in Sweden between 1974 and 2001. Of these, more than 24, 000 were diagnosed with endometriosis. The researchers used data from several national registers to map the women's childhood conditions.

Factors such as having parents with mental illness, substance abuse, financial problems or intellectual disabilities, having a teenage parent, death in the family, and being exposed to or subjected to violence and sexual abuse were examined.

The results showed that all factors examined, except death in the family, were linked to an increased risk of endometriosis. Experiencing any of these risk factors was linked to a 20% increased risk of endometriosis diagnosis compared to women who had not been exposed.

"We also saw that the more adverse experiences in childhood, the higher the risk. Among those who had five or more factors, the risk increased to 60%, " says the study's first author, Marika Rostvall, a physician and doctoral student at the Department of Global Public Health at Karolinska Institutet.

The strongest link was observed in children who had been exposed to violence. These children had more than twice the risk of developing endometriosis later in life compared to women who had not been exposed.

"The results suggest that early life experiences can affect the body's health much later in life and highlight the importance of looking at the whole person, not just the symptoms. The findings are also in line with previous research showing that difficulties in childhood have profound consequences for future health, " says Rostvall.

Research has not yet established the link between difficult childhood experiences and endometriosis, but Rostvall highlights two possible explanations.

"One explanation is that stress during childhood can affect the immune system, which could prevent it from effectively eliminating endometriosis tissue.

"Another explanation is that trauma during childhood could affect the body's sensitivity to pain, which can lead to increased pain and thus a higher likelihood of being diagnosed with endometriosis, " says Rostvall. "I hope that the findings can be used to improve both preventive measures and treatment in health care.

As the study is observational, it is not possible to draw conclusions about causal relationships. The research is a collaboration between Karolinska Institutet and the Center for Epidemiology and Community Medicine (CES), Region Stockholm.

More information: Marika Rostvall et al, Adverse childhood experiences and the risk of endometriosis – a nationwide cohort study, Human Reproduction (2025). DOI: 10.1093/humrep/deaf101  Journal information: Human Reproduction