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 Limb–body wall complex (LBWC) refers to a combination of multiple malformations involving the craniofacial structures, thoracoabdominal wall, extremities, and spine. LBWC is almost uniformly lethal and associated with a very poor outcome because of, among other factors, pulmonary hypoplasia.…
Introduction Although umbilical vascular anomalies are congenital malformations seen commonly, venous abnormalities of the umbilical vein, such as an umbilical cord varix, are rare. The widespread use of routine sonography has facilitated the prenatal diagnosis of umbilical vein varix (UVV),…
Introduction The widespread use of high-resolution ultrasound (US) in routine obstetric care has led to greater detection of placental and umbilical cord abnormalities. Cysts of the umbilical cord have been reported in all trimesters. The clinical significance and prognosis of…
Introduction Amniotic band sequence (ABS) refers to a broad group of highly variable congenital anomalies involving multiple fetal structures. Embryologically normal fetal structures become entangled in amniotic bands, leading to constriction, disruption, and malformation defects. The term sequence describes this…