Three-dimensional ultrasonographic diagnosis of a cervical pregnancy.

Cervical pregnancy is a rare condition characterized by implantation of a fertilized ovum in the endocervical canal below the internal os level; its incidence is less than 0.1% of all ectopic pregnancies. Although predisposing factors have been described, the cause of cervical pregnancy remains unknown. Cervical pregnancy has a high morbidity potential due to massive hemorrhage that can be associated with it, but mortality is low due to early ultrasonographic diagnosis, using transvaginal examination. Making a differential diagnosis between cervical pregnancy and isthmic pregnancy is very important for prognostic reasons, since cervical pregnancy is not compatible with viable pregnancies, while an isthmic pregnancy can reach viability and term. However, making the correct diagnosis using conventional 2-dimensional ultrasonography (2D-US) remains a challenge. Magnetic resonance imaging (MRI) has been used in few cases of cervical pregnancy to improve diagnostic accuracy. So far, to our knowledge, 3-dimensional ultrasound (3D-US) has not been described in this situation. The present article presents a case of cervical pregnancy diagnosed by transvaginal 3DUS examination.