One third of women using fertility treatments are being diagnosed with endometriosis after they begin, with late diagnosis reducing their chance of having a successful pregnancy.
Katrina Moss, a public health researcher from the University of Queensland, is the lead author of the study, published in the journal, Human Reproduction.
Dr Moss said up to 40 percent of women with endometriosis will need fertility treatment compared to women without endometriosis.
The condition, where endometrial tissue grows outside of the uterus, affects 1 in 9 women in Australia and on average takes 6.5 years to be diagnosed.
“For women who had endometriosis but didn’t know about it when they started their fertility treatment, they were just worse off,” Dr Moss said.
“They did more cycles, they were more likely to use intrauterine insemination (IUI), compared to in-vitro fertilisation (IVF), which is the recommended treatment.”
According to her research, these women were also 33 percent less likely to have a baby compared to women without endometriosis.
However, the research also found women who knew about their endometriosis before starting fertility treatment were no different on any outcome compared to women without the condition.
“Knowing about your diagnosis levelled the playing field,” Dr Moss told the ABC’s Emma Pollard.
Dr Moss explained that she has personal experience with endometriosis – she was diagnosed with the condition in her twenties.
She has been through 12 cycles of IVF and seven embryo transfers, without success.
“The success rate for things like IVF is pretty low really, you wouldn’t wish it on your worst enemy … it’s a very difficult process,” she said.
“It’s not what I would have planned and it’s not what I chose.”
“I would just really love other women to know they’re not alone in what they’re going through and that early diagnosis does make a difference for some women.”
Dr Moss said the women in her study with undiagnosed endometriosis “did so many more cycles than women who knew about it”.
“When you take into account the financial and emotional burden of that, they’re just going through so much more that they didn’t need to go through if they had this knowledge at the start,” she said.
“Fertility treatment is tough and it’s even tougher if you have undiagnosed endometriosis.”
Dr Moss’ study used data from the Australian Longitudinal Study on Women’s Health and focused on the experiences of 1,322 women who used Assisted Reproductive Technology (ART).
Hayden Homer, a Brisbane-based fertility specialist, said it was the first study of its kind in Australia to examine the “real-life impact of endometriosis on fertility”.
“This group of patients were followed up for 20 years … so it is a representative data set on how their fertility progressed and how endometriosis impacted,” Professor Homer told the ABC.
He believes IVF is a “superior treatment” for women with endometriosis over “simpler forms” of assisted reproduction such as IUI, since endometriosis is thought to cause “very high levels of inflammation in the pelvis”.
“In that environment, if sperm and eggs are exposed to that inflammatory response, their ability to form an embryo that can plant is affected,” Professor Homer said.
“So if you did IVF, you remove the eggs and sperm from that environment and they are put together in the lab and the embryos are cultured outside of that level of inflammation.”
Professor Homer doesn’t believe all women with fertility issues should be lining up to get surgical testing for endometriosis.
“The only way to definitively diagnose a majority of endometriosis is to have a laparoscopy, which is obviously quite invasive,” he said.
“We’re not saying everyone who has a fertility problem should have a laparoscopy and that’s because based on this study – and consistent with other data – only about 35 percent of women seeking ART have endometriosis.”
“If we did laparoscopy for everyone, two out of three people would have an unnecessary operation.”
Professor Homer noted pain as a “red flag” for endometriosis.
“Significant pain that keeps you off work, pain with intercourse, pain with opening the bowels and so on.”
He remarked that for women with those symptoms an ultrasound scan “is a very good initial sort of screening process … and you’d prioritise for further investigation”.