The goal of this clinical trial is to investigate the added value of three-dimensional transvaginal ultrasound (3D TVUS) and gel infusion sonography (3D GIS) for diagnosing a partition in the uterus (uterine septum) in comparison to magnetic resonance imaging (MRI). The main question it aims to answer is:

How well do 3D TVUS and 3D GIS detect a uterine septum compared to MRI?

Participants will receive 3D TVUS/ 3D GIS and MRI, and will complete questionnaires.

Inclusion Criteria:

• Women aged between 18 and 45 years
• With suspicion of a uterine septum on routine 2D TVUS
• Who are willing to give informed consent

Exclusion Criteria:

• Women aged below 18 years and over 45 years
• Prior definitive diagnosis of a uterine septum or other congenital uterine anomaly
• Prior surgery in relation to a uterine septum
• Cervical (unilateral) aplasia
• Vaginal aplasia
• Untreated obstructive vaginal septum
• Any co-morbidity that is found to interfere with the uterine measurements required in the study
• Contraindications for MRI
• Not willing or not possible to undergo transvaginal ultrasound
• Pregnancy at the time of inclusion
• Wish to conceive between inclusion and last diagnostic intervention
• Visual or pathological evidence of cervical, uterine or ovarian malignancy
• Patients with an intrauterine device (by mistake), who are not willing to remove this device before the start of the diagnostic interventions

Central readers of US and MRI images