Cornual, interstitial, and angular pregnancies: clarifying the terms and a review of the literature.

The terms "cornual," "interstitial," and "angular" pregnancies are used inconsistently in the literature. Some sources use "interstitial" and "cornual" synonymously, while others reserve "cornual" for gestations in bicornuate or septate uteri; others distinguish interstitial from angular pregnancy, while in practice, many physicians are unfamiliar with the latter designation. This article aims to clarify the terms and review the literature with respect to diagnosis and prognosis, with attention to the potential roles of 3D ultrasound and magnetic resonance imaging.