Abstract
Study question
What’s the incidence of class U1-U6 CUAs in subfertile women? What’s the clinical pregnancy rate in women with the most common anomaly, a septate uterus?
Summary answer
The incidence of CUAs is 5.9% in our subfertile population, with a septate uterus (U2) being the most common abnormality in 4.2% of the population
What is known already
Congenital uterine anomalies (CUAs) are common. A systematic review suggested an estimated overall prevalence of 5.5% in an unselected population, 8.8% in the subfertile population, 13.3% in those with a history of recurrent miscarriage and 24.5% in those with a history of subfertility and recurrent miscarriage. A septate uterus (U2) is the most common CUA and is amenable to surgical intervention although at present there is a lack of evidence suggesting benefit in subfertile patients. Women with a septate uterus are known to have poorer reproductive outcomes, including reduced conception rate and increased first trimester loss.
Study design, size, duration
All patients referred to our department for subfertility had a 2D pelvic ultrasound scan as part of their baseline investigations. Since it was established in 2016, all patients with a suspected CUA based on clinical history and investigations, were referred to the clinic and data collected prospectively. Prior to this, women with suspected CUAs required a hysteroscopy or MRI scan for confirmation of diagnosis, often leading to long waiting lists and treatment delays.
Participants/materials, setting, methods
Out of the 4716 patients referred to the department for subfertility from 2016–2018, 302 women were referred to the 3D clinic due to suspicion of a CUA. Transvaginal 3D-ultrasound scan was performed and CUAs classified according to the ESHRE/ESGE working groups. Patients diagnosed with a septate uterus were given options of conservative versus surgical treatment, in the light of unclear benefits of hysteroscopic septum resection. Clinical pregnancy data were collected about this cohort.
Main results and the role of chance
Of the 302 women referred to the service, the uteri of 25 patients were unable to be assessed accurately, most commonly as the cavity was unclear due to a thin endometrium. The remaining 277 patients were classified as having the following CUAs; Normal (U0) 63 patients, Dysmorphic (U1) 5 patients, Septate (U2) 199 patients, Bicorporeal (U3) 6 patients and Hemi uterus (U4) 4 patients. No women were classified as having an aplastic uterus (U5) or unclassified (U6).
Of the 199 women with a septate uterus, 15 women opted for surgical intervention, 143 women decided to have conservative management and 41 women were lost to follow up. The women who had hysteroscopic resection of the septum had a mean age of 35 years, 6/15 had primary subfertility and 6/15 had a history of recurrent miscarriage. The women who had conservative management had a mean age of 32.5 years, 100/143 had primary subfertility and 20/143 had a history of recurrent miscarriage. At present, 89/143 women who have had conservative management and 12/15 women who had surgical interventions have had a clinical pregnancy, 72/89 and 6/12 of these pregnancies were IVF/ICSI pregnancies respectively.
Limitations, reasons for caution
This is an observational study, these findings can be useful for patient counselling. However, ideally randomised controlled trials are needed as evidence for the different treatment options for the cohort of patients with septate uterus, which are largely lacking in the current literature, as their feasibility remains a challenge.
Wider implications of the findings: Three-dimensional transvaginal ultrasonography clinics are cost-effective one-stop services, successfully providing a diagnosis and management plan in 92% of patients referred with a suspected CUA. They increase patient satisfaction by providing an opportunity to discuss risks in future pregnancies and reducing reliance on hysteroscopy and MRI scans.
Trial registration number
Not applicable
The Role of Three-dimensional Ultrasound in the Assessment of Congenital Uterine Anomalies
