Introduction Twin pregnancies account for more than 3% of live births in the United States. Determination of chorionicity and amnionicity is essential in the clinical management of multiple gestations. Although dichorionic twin gestations are not associated with as many fetal…
Introduction Compared with dichorionic twin gestations, monochorionic twin gestations, whether diamniotic or monoamniotic, have an increased risk of adverse pregnancy outcomes. Ultrasound (US) plays a vital role in prenatal determination of chorionicity and in the management of monochorionic diamniotic twin…
Introduction In addition to the general risks associated with twin pregnancies and with specific risks of monochorionic gestations, monoamniotic twin gestations face the unique risk of cord entanglement and are at increased risk of fetal demise. Ultrasound (US) plays a…
Introduction In 2014, the twin birth rate in the United States rose to an all-time high of 33.9 per 1000 live births. Multiple gestations result from either the fertilization of multiple ova or the division of a single fertilized ovum…
Introduction Vasa previa is a condition in which the umbilical vessels course through the membranes within the lower uterine segment and traverse over, or near, the endocervical os. These vessels can rupture spontaneously without rupture of the membranes, and result…
Introduction Placenta previa is a leading cause of antepartum bleeding. Diagnosis of this condition prenatally by ultrasound (US) is key in preventing the significant maternal and fetal morbidity that can occur as a result of this condition. Disease Definition Placenta…
Introduction Gestational trophoblastic disease (GTD) is a spectrum of disorders arising from abnormal proliferation of the trophoblastic epithelium of the placenta. There are several histologically distinct types of GTD that range from premalignant, complete, and partial hydatidiform moles (HMs), to…
Introduction Circumvallate placenta is a placental anomaly in which the membranous chorion transitions to a villous chorion, not at the placental edge, but at an area inward from the placental margins, closer to the insertion of the umbilical cord. This…
Introduction Malignant gestational trophoblastic disease (GTD) occurs when there is clinical, radiologic, pathologic, or hormonal evidence of persistent trophoblastic tissue, or abnormal growth of trophoblastic tissue. This is most commonly diagnosed after a molar pregnancy, but it can occur after…
Introduction Chorioangiomas are the most common histologic type of placental tumor. They are usually well circumscribed, vascular, and predominantly hypoechoic, ranging from microscopic to several centimeters in diameter. Disease Prevalence and Epidemiology Chorioangiomas are found in 0.5% to 1% of…