Dilemmas in the 18-week morphology scan: a review

The 18-20-week obstetric ultrasound scan is a commonly performed radiological investigation. The sonographic abnormalities demonstrated and management implications change frequently. A tertiary referral centre such as the Women's and Children's Hospital receives many queries from radiologists regarding the further management of their patients. The more common problems have been addressed by using a systematic approach to fetal anatomy, and emphasis is placed on the need for standardized protocols. The object of this review is to provide an obstetric morphology scan update.