Are Early Pregnancies Implanted Close to the Tubal Ostia at Increased Risk of Miscarriage? A Prospective Observational Study

The aim of this study is to establish clinically meaningful ultrasound-based diagnostic criteria for AP. To this end, the investigators will prospectively collect clinical and ultrasound data from early intrauterine pregnancies and correlate this data with pregnancy outcomes (particularly with risk of miscarriage), to establish whether there are any diagnostic criteria that can be used to make the diagnosis, facilitate increased surveillance of at risk pregnancies and reassure those with normally located pregnancies. The collected data will be used to correlate incidence of angular pregnancy and clinical variables such as maternal age, uterine fibroids, assisted conception, multiple pregnancy, ethnicity, previous uterine and adnexal surgery.