(Reuters Health) - Women who were abused as children may be more likely to develop endometriosis in adulthood, separate studies suggest.

The authors of a European report in the journal Human Reproduction found a 20 percent to 50 percent increased risk of developing endometriosis with a history of sexual or emotional abuse, while the authors of a large U.S. study in the same journal found similar increase in risk with sexual or physical abuse.

“We decided to do this study because there is increasing evidence that childhood maltreatment has a serious impact on many adult diseases,” said senior author of the European study, Dr. Brigitte Leeners, a researcher at University Hospital Zurich in Switzerland.

“Childhood maltreatment is often an underestimated and un-investigated risk factor for different adult diseases,” Leeners said in an email.

Endometriosis is a painful condition that occurs when tissue that normally lines the uterus migrates to other parts of the body - usually the abdomen or pelvis. It’s one of the most commonly diagnosed gynecologic conditions for women of reproductive age, affecting roughly 10 percent of U.S. women.

“Previous studies that members of our research team had been involved with had shown an association between early-life abuse and both uterine fibroids (another common gynecological condition) and hypertension,” said the lead author of the U.S. study, Holly Harris of the Fred Hutchinson Cancer Research Center in Seattle.

“Given recent links found between endometriosis and hypertension, one of the next logical steps was to examine the association between abuse and endometriosis,” Harris said in an email.

Leeners and her colleagues compared 421 women who had been diagnosed with endometriosis to 421 women without the condition attending the same medical clinics at university hospitals and private doctor’s offices in Austria, Germany and Switzerland.

Based on responses to a childhood trauma questionnaire, the researchers found that women with endometriosis more often reported a history of sexual abuse, emotional abuse, emotional neglect and inconsistency experiences.

Harris and her team examined data from the Nurses’ Health Study II, which included women from across the U.S. Among more than 60,000 women who answered questionnaires about lifetime exposure to violence, about 3,400 endometriosis cases were diagnosed during 24 years of follow-up.

The study team found that compared to women with no history of abuse, the risk of endometriosis rose by 10 percent with a history of physical abuse and 15 percent with a history of sexual abuse. Women who reported being abused both physically and sexually were 31 percent more likely to be diagnosed with endometriosis.

But severity and duration of the abuse was also a factor.

Women with a history of severe childhood sexual abuse continuing into adolescence had a 49 percent increase in risk for endometriosis. The combination of severe and chronic abuse or multiple types of abuse in childhood was tied to a 79 percent rise in risk.

“Abuse in childhood and adolescence is far too common, in both women with, and without, endometriosis,” Harris said.

In the study population, for example, 34 percent of all women reported a history of moderate or severe physical abuse and 39 percent of women with endometriosis reported this type of abuse, she noted.

“These numbers are too high for all women and reducing abuse is a public health issue,” Harris said.

In addition, Harris said that while the researchers found a clear association between early-life abuse and endometriosis, it does not mean that all women with endometriosis have experienced abuse.

“It may be a stress response to the trauma that activates these systems and causes a woman to be more sensitive to pain from endometriosis lesions,” she said. That is not to say that the pain is in the women’s heads. “It’s due to a physiologic response that’s driven by the stress and trauma of abuse,” Harris emphasized.

“We expect that early intervention to reduce consequences of childhood maltreatment, for example, different forms of psychotherapy would also reduce the risk for endometriosis - however, this needs to be confirmed in future studies,” Leeners said.

SOURCE: bit.ly/2KsbdZt and bit.ly/2JYOC2i Human Reproduction, online June 26 and July 17, 2018.