Fertility
Endometriosis linked to reduction in live births before diagnosis of the disease, study finds
Until now, little has been known about the possible effects of endometriosis on fertility, especially in the years before a diagnosis

Endometriosis may be linked to a reduction in fertility in the years preceding a definitive surgical diagnosis, researchers from Finland have found.
In the first study to look at birth rates in a large group of women who received a surgical verification of endometriosis, scientists discovered that the number of first live births in the period before diagnosis was half that of women without the painful condition, regardless of the form of endometriosis.
The research team also found evidence that the number of babies women had before endometriosis was diagnosed was significantly reduced, compared to women without an endometriosis diagnosis.
“Our findings suggest that doctors who see women suffering from painful menstruation and chronic pelvic pain, should keep in mind the possibility of endometriosis and treat them effectively,” said Professor Oskari Heikinheimo of Helsinki University Hospital, who led the study.
“Doctors should discuss with these women the possible effects on their fertility, in addition to the effects of their age, and the impairment of fertility should be minimised by offering relevant treatment for endometriosis without delay.”
Endometriosis is a chronic inflammatory condition where tissue similar to the lining of the womb grows in other places, such as the ovaries and fallopian tubes, affecting up to about 10 per cent of women of child-bearing age.
Typical symptoms include painful menstruation, pain in the pelvic area, difficult or painful sexual intercourse, and difficulty getting pregnant. Surgery has traditionally been the “gold standard” for diagnosing the condition and classifying the type of endometriosis, although diagnosis by ultrasonographic findings or the symptoms alone is currently accepted.
Until now, there has been little information about the live birth rate among women with endometriosis, and little is known about the possible effects of different types of endometriosis on fertility, especially in the years before a diagnosis.
“Given the chronic nature and typical long delay in diagnosis of endometriosis, we wanted to find out if there were differences in first birth rates before diagnosis in a large group of women in the population,” Professor Heikinheimo explained.
He and his colleagues looked at 18,324 women in Finland, aged between 15 and 49 years, who had surgical verification of endometriosis between 1998 and 2012. They matched them with 35,793 women of similar age who did not have an endometriosis diagnosis.
The follow-up period started at the age of 15 years, and continued until the first live birth, sterilisation, removal of the ovaries or womb, or until the surgical diagnosis of endometriosis, whichever came first.
The group of women with endometriosis were also divided into four groups according to the type of endometriosis.
A total of 7,363 women (40 per cent) with endometriosis and 23,718 women (66 per cent) without endometriosis delivered a live born baby during the follow-up period. The incidence rate of first live births among women with endometriosis was half that of women without the condition.
When analysed according to women’s birth decade from 1940s to 1970s, the birth rate decreased in both groups of women. Importantly, over the decades, an increasingly lower first live birth rate was seen in women with endometriosis, compared to women without.
In those women born in 1940-1949, the difference in live birth rates between the two groups was 28 per cent before surgically diagnosed endometriosis, but this difference increased steadily to 87 per cent by 1970-1979, the study showed.
“We assume that this is associated with the older age of women when they have their first baby, earlier surgical diagnosis of endometriosis and accumulating adverse effects of endometriosis in women affected by the condition,” said Heikinheimo.
“The possible effect of endometriosis on the desired number of children highlights the importance of early diagnosis and treatment of the disease,” he said, noting that the number of children that women had before their diagnosis of endometriosis was 1.93 and 2.16 for women without endometriosis.
“It is important to note that this study reports on live births before a definitive diagnosis of endometriosis,” the researcher added.
“Next, we will be reporting on the fertility rates after the surgical diagnosis and treatment of endometriosis. We hope that the fertility of women with endometriosis catches up with that of the women without the condition after surgical management.”
Although important, the study comes with some limitations. These include its focus on only surgically-confirmed endometriosis, which may have ruled out women with milder symptoms who were treated for the condition.
There were no data available on whether or not women wanted to become pregnant. The researchers could not rule out the possible effect of fertility treatments or the effect of adenomyosis, which is known to occur often with endometriosis, and which also affects fertility and pregnancy outcomes.
Differences in socioeconomic and educational backgrounds between the two groups of women might have also affected the findings, the researchers noted.
Entrepreneur
Applications open for the third W Accelerate with Merck KGaA and M Ventures

W Group has opened applications for W Accelerate with Merck KGaA and M Ventures, inviting reproductive and maternal health startups, scaleups and spinouts to pitch for direct access to global pharma partnership and strategic investment.
Selected companies will pitch on 5th October, competing for the chance to accelerate their growth through commercial partnerships, investment, or both.
This is the third time Merck KGaA, a global leader in reproductive health, has partnered with W Group on the programme, which exists to close the innovation and investment gap in women’s health by connecting the sector’s most promising startups directly with the corporates and investors positioned to scale them.
What Merck KGaA and M Ventures are looking for
This year’s call is focused on breakthrough solutions in female infertility, fertility preservation, adenomyosis, endometriosis, polyendocrine metabolic ovarian syndrome (PMOS), ovarian insufficiency, preeclampsia and pregnancy comorbidities.
New for this round, applicants choose between three pathways depending on what they need from the programme:
- The Partnership Lane, for companies seeking commercial collaborations and strategic relationships
- The Investment Lane, for founders looking to connect with investors and secure funding to scale
- The Dual Lane, for innovators pursuing both partnership and investment opportunities
How the Accelerate event works
Selected companies get a 1:1 pitch practice session ahead of time, then a private 30-minute session with Merck KGaA and M Ventures leadership on the day itself, small-group sessions with regulatory and investment strategy experts, an “Ask Merck Anything” roundtable, and a VIP networking reception.
Key dates
- Open call launches: 8th July
- Open call closes: 2nd September
- Notification of successful companies: 11th September
- Pitch day: 5th October
Applications are open now at wplatform.typeform.com/to/KGzviBQM.
Fertility
Older women face lower chance of fertility treatment working, even with donor eggs, study finds

IVF success declines with age even when women use young donor eggs, with a marked fall from around 49, research suggests.
The findings challenge the idea that donor eggs can fully “reset” the reproductive clock, although researchers said they should not discourage older couples from trying.
Dr Beatrice Crestani, from an assisted reproduction medical institute in Italy, said reproductive ageing had traditionally been seen mainly as an issue involving the ovaries.
She said replacing older eggs with younger donor eggs was often believed to “reset” the reproductive clock.
Dr Crestani added: “Our findings suggest the picture is more complex.”
The study followed 1,774 women undergoing in vitro fertilisation, or IVF, using donated eggs. IVF involves fertilising an egg in a laboratory before transferring an embryo to the womb.
Women in their mid to late 30s had a 54 per cent chance of becoming pregnant after treatment, compared with around 43 per cent among those aged 49 or older.
Live birth rates fell from 46 per cent to 32 per cent, while miscarriage rates rose from 24 per cent to 38 per cent.
Women aged 49 and older had twice the risk of miscarriage compared with those aged 35 to 40.
Researchers believe changes to the endometrium with age may help explain the difference. The endometrium is the lining of the womb where a fertilised egg or embryo implants and grows.
Although the thickness of the womb lining was similar across the age groups, its condition declined with age.
Researchers said future work might find ways to predict, prevent or improve uterine ageing.
Dr Crestani said: “These findings should not discourage women from pursuing donor-egg treatment, because success rates remain meaningful even at advanced ages.
“However, patients should be counselled that donor eggs cannot completely eliminate the effects of reproductive ageing, particularly beyond 49 years.”
Among women who transferred all their available embryos, the live birth rate was around 80 per cent for those aged 35 to 40 and 62.5 per cent for those aged 49 or older.
Experts stressed that the health of the womb and ovaries differs between women.
There is no legal upper age limit for IVF in the UK, unlike some European countries. Greece has an upper limit of 54.
Women in the UK can donate or share their eggs up to the age of 36.
Regulators ask private UK clinics to assess the welfare of any resulting child and whether the recipient can safely carry a pregnancy.
NHS guidelines recommend offering three IVF cycles to women up to the age of 40 and one cycle to women up to the age of 42.
Patients using donor eggs usually have to fund that part of the treatment themselves.
People conceived using sperm, eggs or embryos from donors registered after 1 April 2005 can request identifying information about their biological donor parent once they turn 18.
The findings are being presented at the European Society of Human Reproduction and Embryology.
Professor Borut Kovacic, chair-elect of the society, said researchers were trying to better understand the “cross-talk” between an implanting embryo and the womb lining. This refers to the biological signals exchanged during implantation.
He said the age threshold associated with the beginning of a loss of uterine function was unlikely to be absolute.
Professor Kovacic added: “It provides important information for patients and offers a valuable foundation for future research aimed at identifying novel biomarkers of uterine ageing.”
Dr Ippokratis Sarris, chair-elect of the British Fertility Society, called for more research.
He said pregnancies could carry greater risks for older women and recommended thorough health checks and counselling for couples beginning fertility treatment.
Insight
Women with PMOS should have annual NHS checks, new guidance says

Women with PMOS should receive annual NHS checks to spot related health risks sooner, according to new draft guidance.
Polyendocrine metabolic ovarian syndrome (PMOS) is a complex condition that can have wide-ranging effects across the body.
It affects around one in eight women and was formerly known as polycystic ovary syndrome. It was renamed in May to better reflect its broader effects.
Draft guidance from the National Institute for Health and Care Excellence (NICE) calls for quicker diagnosis and better monitoring.
Marie Anne Ledingham, consultant clinical adviser for women’s and reproductive health at NICE, described the recommendation for a “simple” annual review as an “important step”.
She said: “This new guideline will help improve consistency of care, increase awareness of the condition, and support earlier diagnosis and management.”
PMOS is a major cause of female infertility. Symptoms can include irregular or absent periods, difficulty becoming pregnant, excessive facial or body hair, weight gain, hair loss, oily skin and acne.
An estimated three million to four million women have the condition in the UK, but NICE says it remains underdiagnosed and inconsistently managed.
The proposed annual reviews would cover current symptoms and longer-term health risks linked to the condition, including diabetes and heart disease.
NICE says lifestyle changes and treatment could help prevent more serious illness.
There is no cure for PMOS, but NHS treatments can help manage its symptoms. These include hormone support and fertility drugs.
The draft guideline does not recommend laser or light therapies for hair reduction because of the cost.
Many women report difficulty understanding the possible cause of their symptoms or experience delays before receiving a diagnosis.
When doctors suspect PMOS, they may use blood tests to assess hormone levels and ultrasound scans to look for the multiple follicles often seen on the ovaries of those affected. Follicles are small, fluid-filled sacs in which eggs develop.
The draft guideline sets out when healthcare professionals should suspect the condition and how women should be assessed and diagnosed.
It also says PMOS should not be ruled out in women who have been through the menopause.
The condition is thought to be more common among black, Asian and mixed-ethnicity women. NICE says healthcare professionals should consider this when assessing symptoms.
PMOS can also have a significant effect on mental health and quality of life, with depression and anxiety described as common among women with the condition.
Women planning a pregnancy should receive advice on weight, diet, nutrition, exercise, sleep and mental health, according to the guidance.
The draft guideline is open for consultation from 1 July to 11 August 2026, with feedback invited from healthcare professionals, patients and the public.
The final guideline is expected to be published in December 2026.
Entrepreneur2 weeks agoXella launches AI-powered precision health platform
Cancer2 days agoThousands of women could avoid painful cancer exam with new AI blood test
Insight4 days agoWomen with PMOS should have annual NHS checks, new guidance says
Diagnosis3 days agoTwo “gamechanger” tests set to speed up endometriosis diagnosis on the NHS
Entrepreneur1 week agoKorea’s Femtech Industry Goes Global as Vespexx Hosts Korea Femtech Summit 2026
Fertility2 weeks agoImmunotherapy may temporarily restore fertility in premature menopause
News7 days agoBreast cancer biosensor and low-cost ultrasound startups win women’s health AI competition
News2 weeks agoDon’t miss HTW’s upcoming deep dive into health AI












