The early prenatal sonographic diagnosis of renal agenesis: Techniques and possible pitfalls

Out of 13 252 cases in which fetal bilateral echogenic kidneys were detected by transvaginal sonography between 12 and 18 weeks' gestation, there were nine fetuses where oval hypoechogenic masses were detected in the renal bed. In five fetuses where hypoechogenic masses in the renal bed were sonographically visualized, postabortal examination was compatible with renal agenesis and the hypoechogenic masses proved to be enlarged adrenals. In three additional cases, unilateral renal agenesis was accompanied by unilateral enlarged adrenals, radiologically confirmed postnatally. In one case, a false-positive sonographic diagnosis of Potter syndrome was made because of bilateral hypoechogenic masses in the renal bed. Postabortal examination detected hypoplastic kidneys, but of normal histology, in a dyskaryotic fetus with trisomy 22. In four cases of renal agenesis, the amniotic fluid was of normal volume until the 17th week. In two of the five cases of Potter syndrome, a cystic structure, compatible with the urinary bladder, was detected in the pelvis at 14 weeks. The diagnostic criteria for renal agenesis in the early fetus differ from those used in the second half of gestation.     

Prenatal diagnosis of ventricular septal defect and overriding aorta at 14 weeks' gestation,using trans vaginal sonography

Two fetuses with heart abnormalities were detected by transvaginal sonography at 14 weeks of gestation. In the first fetus, a ventricular septal defect and an overriding aorta were detected and a diagnosis of tetralogy of Fallot was suggested. In addition, cystic hygroma and omphalocoele were visualized and the cytogenetic study revealed trisomy 18. In the second fetus, ventricular septal defect, pericardial effusion, and omphalocoele were detected.     

Visualization of fetal intra-abdominal organs in second-trimester severe oligohydramnios by intraperitoneal infusion

Fetal intraperitoneal infusion of saline was performed in two patients with severe oligohydramnios at 24 and 25 weeks' gestation in order to enhance visualization of intra-abdominal organs. Renal agenesis was easily diagnosed. The technique can be considered as an alternative to artificial instillation of amniotic fluid in the differential diagnosis of conditions associated with severe oligohydramnios.