Condition linked to difficulty conceiving could be under-diagnosed

Many women who have difficulties conceiving do not get a clear reason from their medical professional, so researchers from Tommy’s National Centre for Miscarriage Research are looking into conditions which can cause difficulty conceiving and carrying a pregnancy to term.

Tommy’s researchers analysed 21 previous studies on adenomyosis - a condition where the cells of the lining of the womb (endometrium) are found in the muscle layer of the womb (myometrium) - to find out how common it is in women with reduced fertility.

Adenomyosis is known as the ‘sister condition’ of endometriosis. However, compared to endometriosis – when womb lining grows outside the womb – adenomyosis is lesser-known.

Adenomyosis has previously been associated mostly with women over 40 presenting with a heavy and painful menstrual cycle but there’s growing evidence to suggest it may be present earlier in life and in women with subfertility.

About one third of women with adenomyosis experience few or no symptoms. Others experience heavy and/or painful periods, premenstrual pelvic pressure, pelvic pain, painful sexual intercourse and reduced fertility.

There’s also currently a lack of a good quality evidence available on the impact of adenomyosis on fertility or whether it could be connected to miscarriage, which is something Tommy’s researchers intend to explore.

Through a review published in the journal Ultrasound in Obstetrics and Gynecology in January, a research team led by Dr Ishita Mishra found that among the 25,600 women with ‘subfertility’ studied across 21 previous research projects, 10% had adenomyosis; 10% had adenomyosis with coexisting fibroids; 18% had adenomyosis with coexisting endometriosis; and 17% had adenomyosis with coexisting endometriosis and fibroids.

This suggests that 1 in 10 women with reduced fertility have a diagnosis of adenomyosis.

The review found that an internal examination of the womb using a transvaginal ultrasound is the most widely available first line tool to diagnose adenomyosis, followed by an MRI scan.

Researchers also found inconsistencies in how it is diagnosed across the studies, which means that adenomyosis could be potentially underdiagnosed.

While ultrasound guidelines published in 2015 describe a standardised and uniform way to diagnose adenomyosis on ultrasound, our researchers found that there was a wide variation in the number and type of ultrasound features used by healthcare professionals to establish the diagnosis of adenomyosis which means that mild cases of adenomyosis could be missed.

This mirrors research into the diagnosis of other uterine conditions like endometriosis, which has an average time of 8 years from symptoms to diagnosis. Delays in diagnosing conditions can impact on how clinicians investigate and treat fertility problems.

Lead author of the review, Dr Ishita Mishra, says:

Our review shows that the diagnostic criteria for diagnosing adenomyosis varies widely, so it is difficult to make an estimate of how common this condition is. It also means some cases may be missed, which could impact on how women’s fertility issues are investigated and understood.

There should be training for clinicians and sonographers to diagnose adenomyosis using a standardised criteria. Being able to identify this condition using a uniform set of criteria would then help give us a true picture of the numbers affected, and better understanding of the impact of this condition on pregnancy complications and loss.

Dr Mishra and colleagues at the Tommy’s National Centre for Miscarriage Research in Birmingham will now be using their review as the basis for new work investigating how adenomyosis could be linked to risk of miscarriage.