Prenatal sonographic findings of prominent fetal tricuspid annulus: A case report.

The tricuspid valve positioned between the right atrium and right ventricle is composed of 3 leaflets (anterior, posterior, and septal) anchored by a collagenous fibrous annulus, a saddle-shaped, oval structure, providing a firm yet dynamic structural support for the tricuspid valve. The annulus is considered to separate between the right atrium and right ventricle. Structural anomalies of the fetal tricuspid valve are rare and include Ebstein's anomaly, tricuspid atresia, partial absence, unguarded tricuspid orifice (absent leaflets) cleft, double orifice, bicuspid valve and Uhl anomaly (absence of the right ventricular myocardium with an apposing endocardium and epicardium). We present an unusual case in which a prominent peripheral circular structure was noted above the periphery of the fetal tricuspid valve at 31 weeks' gestation. Inflow across the tricuspid valve was unimpaired, with no tricuspid regurgitation. The right atrium appeared normal with a normal functioning foramen ovale, and the entire fetal cardiac anatomy and function were normal with no signs of congestive cardiac failure or fetal hydrops. The prominent non-obstructing circular structure in immediate proximity to the tricuspid valve leaflets was considered to represent a prominent tricuspid annulus. An appropriate for gestational age fetus was delivered at term and neonatal echocardiography was normal. This case emphasizes that normal variations in fetal anatomical structures should always be considered and specifically that unimpaired inflow across the tricuspid valve in diastole is key upon encountering an unusually prominent fetal tricuspid annulus, which may be noted at a considerable distance above the tricuspid leaflets within the right atrium.

First-trimester septated cystic hygroma, marked non-immune fetal hydrops, 45,X and coarctation of the aorta with neonatal survival.

Marked first-trimester nonimmue hydrops fetalis and 45,X with neonatal survival.

Reverse diastolic flow of the fetal middle cerebral artery associated with placental chorangiomatosis and asymptomatic concealed placental abruption.

Reverse diastolic flow of the fetal middle cerebral artery is a rare, yet ominous finding which has been associated with adverse perinatal outcomes including: intracranial hemorrhage, growth restriction, fetal-maternal hemorrhage, severe anemia, hydrops, hepatic anomaly, subsequent stillbirth, and early neonatal death. We report a case in which following notation of a nonreassuring fetal heart rate at 32 weeks' gestation, sonographic documentation of persistent reverse diastolic flow of the fetal middle cerebral artery was noted in association with sonographic findings of vascular placental dysmorphology and an asymptomatic concealed placental abruption. Subsequent fetal heart rate tracing consistent with uteroplacental insufficiency led to immediate Cesarean birth of an anemic yet nonacidotic, nonhypoxic neonate, who did well following management of respiratory distress syndrome and partial exchange transfusion. Placental abruption was confirmed at delivery. Histopathology of the placenta confirmed the presence of localized chorangiomatosis ("wandering" chorangioma). The association of reverse diastolic flow of the fetal middle cerebral artery, placental chorangiomatosis and placental abruption has not been reported previously. We conclude that in the presence of prenatal sonographic findings of placental dysmorphology and or placental abruption, insonation of the fetal middle cerebral artery should be performed to assess the possibility of increased peak systolic velocity and possible reverse diastolic flow, both associated with fetal anemia and increased likelihood of an adverse perinatal outcome.

Prenatal sonography of extracorporeal ductus venosus in association with large fetal gastroschisis.

Liver herniation commonly associated with omphalocele occurs in only approximately 2.3% to 16% of fetuses with gastroschisis. Liver herniation in such cases is associated with considerably decreased survival rates (43% vs 97% with or without liver herniation, respectively). Rarely, abnormally positioned fetal hepatic vasculature has been reported mainly in association with congenital diaphragmatic hernia. In these rare cases, intrathoracic depiction of hepatic venous vasculature has assisted in confirming intrathoracic displacement of the fetal liver. We present a case of a large gastroschisis with complete herniation of the fetal liver in which prenatal sonography depicted an extracorporeal ductus venosus.