Sonography of the gravid uterus and placenta: current concepts.

Examination of the placenta and gravid uterus is an integral part of any obstetric sonographic study. Fetal well-being and growth depend on an intact uteroplacental vascular supply, and sonography can show most of the macroscopic abnormalities that may adversely affect the placenta or the gravid uterus, and thus compromise the fetus or affect the mode of delivery. The first part of this review will highlight sonography of normal uterine anatomy and pitfalls and review sonographic findings in cases of incompetent cervix, premature labor, and uterine synechiae. The second part will describe some recent advances in sonography of normal placental development and appearance, sonographic and anatomic variations, placental lesions, and implantation abnormalities.