<div>Endometriosis is a common health condition affecting women of
reproductive age who often present with chronic pelvic pain and/or
infertility. There is wide variation in the estimates of endometriosis
prevalence. Accurate reporting of the disease prevalence is hampered by
multiple factors including long delay in diagnosis due to natural
fluctuation in symptoms severity, lack of a reliable non-surgical
diagnostic tool, polymorphic appearance of endometriosis lesions at
laparoscopy, inability to achieve histological confirmation is all
suspected cases and tendency for disease recurrence. Therefore, a
longitudinal, rather than cross-sectional, cohort study design spanning
an extended follow-up period is better suited to assess endometriosis
prevalence. In this issue of BJOG, Rowlands and colleagues (2020) linked
longitudinal survey data to three administrative health databases to
identify the prevalence of endometriosis among 13,508 young Australian
women followed up for nearly 20 years. The study reported a 6%
cumulative prevalence of clinically-confirmed endometriosis and an
additional 5.4% of clinically-suspected endometriosis. If these figures
reflect the true prevalence of endometriosis, then one in nine women
will be diagnosed with endometriosis at some point during their
reproductive years up to the age of 44 with a peak at 30-34 years, thus
underscoring the significant impact of the disease on the well-being and
quality of life in young women and the enormous burden on healthcare
resources needed to diagnose and treat endometriosis and its sequelae.</div><div>The data presented in the study of Rowlands and colleagues (BJOG 2020)
included patients who could have been diagnosed with adenomyosis but
their condition was coded as endometriosis. This is unlikely to have
significantly over-estimated the prevalence of endometriosis as recent
evidence suggests adenomyosis prevalence to be only 1% with a
considerable proportion of those patients having co-existing
endometriosis (Yu et al, Am J Obstet Gynecol 2020; 223: 94.e1-10). The
same can not be said about the 5.4% of clinically-suspected
endometriosis cases. Symptoms review, clinical examination and various
imaging modalities, including ultrasound scanning and magnetic resonance
imaging, represent the cornerstone of non-invasive diagnosis of
endometriosis. Current evidence suggests that the predictive accuracy of
those non-invasive methods in the diagnosis of endometriosis compared to
laparoscopy and histological confirmation is modest (Nisenblat et al,
Cochrane Database Syst Rev, 2016 (2): CD009591) and depends on the
combination of diagnostic tools used as well as the site and extent of
the endometriosis lesions (Reid et al, Eur J Obstet Gynecol Reprod Biol
2019; 234: 171-178). These data are not provided in the study of
Rowlands and colleagues. It is therefore difficult to accurately
estimate the prevalence of endometriosis whether it’s the 6%
clinically-confirmed rate or the full 11.4% confirmed and suspected
rate. The truth probably lies somewhere in the middle! Future
epidemiological studies should endeavour to elucidate on the distinction
between the different methods used in the diagnosis of endometriosis
with reference to the predictive accuracy of each diagnostic modality to
help advance our understanding of the incidence and risk factors
associated with this debilitating gynaecological condition.</div><div></div><div>Mr. Tarek A El-Toukhy</div><div>Assisted Conception Unit, Guys and St. Thomas Hospital NHS Trust</div><div>11th Floor, Tower Wing,Guys Hospital,St. Thomas Street
tarekeltoukhy@hotmail.com</div>