A large prospective study has found that sexual and physical abuse in childhood and adolescence is associated with a greater risk of endometriosis diagnosed during adulthood. The study found that women reporting severe-chronic abuse of multiple types had a 79 percent increased risk of laparoscopically-confirmed endometriosis.

"Both physical and sexual abuse were associated with endometriosis risk, with abuse severity, chronicity, and accumulation of types of abuse each associated with increasing risk in a dose-response manner," said Dr. Holly R. Harris, assistant member of Epidemiology in Fred Hutch's Public Health Sciences Division. She is lead author of an article scheduled to appear July 17 in the journal, Human Reproduction.

Abuse has been associated with chronic pelvic pain, uterine fibroids, and hypertension in previous studies, but this report -- which used data collected from 60,595 women within the Nurses' Health Study II from 1989 to 2013 -- is the first to show an association between childhood abuse and laparoscopically-confirmed endometriosis. Study highlights include:

More than 3,000 cases of laparoscopically-confirmed endometriosis were diagnosed during 24 years of follow-up.

21 percent of all women reported having experienced some level of both child/adolescent physical and sexual abuse.

32 percent reported child/adolescent physical abuse only.

12 percent reported child/adolescent sexual abuse only.

Compared to those reporting no physical or sexual abuse, the risk of endometriosis was greater among those who experienced severe physical abuse or severe sexual abuse.

There was a 79 percent higher risk of laparoscopically-confirmed endometriosis for women reporting severe-chronic abuse of multiple types.

There was a stronger association between early life abuse and pain-associated endometriosis (versus endometriosis diagnosed in the absence of pain).

"A growing body of literature suggests that early traumatic experiences affect production of stress hormones and inflammatory responses, and these contribute to chronic pelvic pain and other pain syndromes. Our findings suggest that similar mechanisms may be involved in the association between early abuse and endometriosis diagnosed during adulthood. We need an increased focus on the potential underlying biological mechanisms to fully understand these relationships," Harris said. "This study adds to the growing evidence that abuse during childhood/adolescence is not rare and can have multiple consequences for lifelong health and wellbeing."

The study population was primarily white female nurses between the ages of 25 to 42 at baseline who were participants in the Nurses' Health Study II, which began in 1989 with 116,429 women. Participants receive follow-up questionnaires every two years.