An Auckland researcher is probing a common cause of period pain and infertility to try to make diagnosis and treatment easier for women.

Women and girls are putting off being tested for a common, debilitating problem because they don’t like the thought of keyhole surgery, says an Auckland researcher.

Reproductive biologist Anna Ponnampalam and a team of collaborators want to find a tell-tale difference in menstruation that could diagnose endometriosis from outside the body. That could make it easier for women to get treated for a disorder that causes serious period pain and infertility.

The fledgling idea still needs funding – but if it goes ahead Ponnampalam wants to place ads in schools, GPs’ offices, and fertility clinics, for women to take part in a trial.

She is also in the early stages of a study trying to pin down an underlying reason for endometriosis.

Because doctors haven’t found a definite cause, women rely on painkillers, contraceptives, and surgery to remove affected tissue and – in severe cases – hysterectomies, to cope with their symptoms.

Ponnampalam, a researcher at the Liggins Institute and a lecturer in gynaecology and obstetrics at University of Auckland’s medical school, says if researchers could find the root cause of hormonal changes in women with endometriosis, they might be able to design more effective treatments to stop the problem at the source.

She is about to start collecting samples of uterine lining from women who’ve had keyhole surgery – both with and without a diagnosis of endometriosis – to look for changes in the way genes are expressed.

Researcher Dr Anna Ponnampalam is looking for epigenetic clues to explain endometriosis. Photo: University of Auckland 

Doctors don’t know why some women and not others have the disorder, which lets endometrial tissue grow outside the uterus instead of only lining the uterus like it is meant to.

Ponnampalam is trying to find out whether endometriosis is caused by an epigenetic effect. These are the moderating influences on our genomes that help explain why, for example, identical twins are different despite having the same DNA. Epigenetic changes could be passed from parent to child, even though they don’t change a person’s underlying DNA.

Ponnampalam is homing in on groups of small hydrocarbon molecules, known as methyl groups, which bind to DNA and which can switch particular genes off.

She says there are signs that endometriosis might be caused by differences in the way the endometrium, or uterus lining, responds to oestrogen and progesterone.

Usually, the hormones oestrogen and progesterone work together to regulate a woman’s menstrual cycle. Oestrogen primes the uterus lining in the first half of the cycle. “During the second half of the cycle, even though there is still some oestrogen around, progesterone takes the centre stage and mitigates the actions of oestrogen,” says Ponnampalam. But in women with endometriosis the endometrium acts differently in response to oestrogen, and progesterone doesn’t take over as it should, a problem doctors call progesterone resistance.

“There might be chemical changes to DNA that may cause progesterone resistance in women with endometriosis,” says Ponnampalam. “We still don’t know how the cascade of events is initiated and that’s what I want to find out.”

If Ponnampalam can find her culprit, that might help explain the disorder and give researchers a clue about where to took for possible treatments.

Unlike our basic DNA, epigenetic effects can be changed by our environments, meaning researchers may be able to tinker with them.

Ponnampalam hopes to have preliminary results by early next year.

Thousands of New Zealand women have endometriosis and many more are believed to have the disorder without knowing.

Often, women put up with painful, even debilitating, periods because they think it is just part of normal menstruation, say researchers. The disorder can affect their sex lives, employment, health and chances of having children.

“Most of the time women get diagnosed only when they figure out they can’t get pregnant,” says Ponnampalam. She says it can take a decade to get a diagnosis, and some women are deterred from investigating because doing so requires a laparoscopy, otherwise known as keyhole surgery. 

The test might be extra off-putting for young girls, says Ponnampalam. “It’s not a serious operation but for a girl it could be significant. It’s still a day in the hospital and putting a hole in your tummy to put a camera through it.”

“Some young girls are reluctant to do that or a gynaecologist might be reluctant to do it for a 13-year old,” she says.

“There are a lot of women and girls who are not diagnosed, but if you look at women with infertility or chronic pelvic pain 50 to 60 percent of them will be diagnosed with endometriosis.”

Other researchers have also been looking for easier ways to spot endometriosis, whether by analysing urine, menstrual blood or other markers.

The Cochrane Collaboration – a group that synthesises clinical evidence for doctors – says a few of these methods show promise, but much more research is needed before any of them could replace keyhole surgery.

For the initial stage of looking for an easier testing method, Ponnampalam will need women who aren’t taking endometriosis treatments or contraceptives that affect their hormones, so she knows any differences she finds in their hormones are because of the disorder.

Researchers hope that earlier, easier diagnosis could reduce the burden endometriosis puts on women, the economy and the health system.

Women who suffer symptoms for a long time often need sick leave, and late diagnosis and treatment can be expensive for both private insurers and the public health system.

Without help there is also a greater chance women will need help conceiving using expensive reproductive technology, say the researchers. 

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