Sonographic genital ambiguity in a fetus due to a mosaic 45,X/46,X,idic(Y)(qter-p11.32::p11.32-qter) karyotype

Nowadays, improved ultrasound techniques enable the detection of more subtle congenital abnormalities at an earlier stage of fetal development. Current cytogenetic techniques can characterize a chromosomal abnormality in greater detail. These advancements in both diagnostic possibilities have helped to answer many questions but have also created new issues and dilemmas in counselling. This is illustrated by this case report of a 35-year-old woman, who presented at the end of the second trimester of her first pregnancy. Sonographic examination indicated an abnormal external genital in a male fetus. A differential diagnosis of hypospadia was made. During follow-up, an amniocentesis was performed, and this showed a 45,X/46,X,idic(Y)(qter-p11.32::p11.32-qter) karyotype as the cause of the sonographic findings. Cytogenetic characterization of the isodicentric Y chromosome and pre- and post-natal findings in the child are reported. Cases with a similar karyotype reported in the literature are reviewed. Copyright © 2005 John Wiley & Sons, Ltd.     

Prenatal identification of a 45,X/46,Xder(Y) mosaicism and confirmation by high resolution cytogenetics and fluorescence in situ hybridization

A 45,X/46,Xder(Y) mosaicism detected prenatally was shown to have a rare Y inversion- duplication or Y/Y translocation which can only be identified by a combination of high resolution cytogenetics and fluorescence in situ hybridization. The present data indicate the usefulness and importance of chromosome-specific probes in the identification and characterization of chromosome rearrangements.     

Fetal magnetic resonance imaging (MRI) of ischemic brain injury

The aim of the present study was to demonstrate the usefulness of fetal magnetic resonance imaging (MRI) in ischemic brain injury. We report seven cases of fetal brain ischemia prenatally suspected on ultrasound (US) and confirmed by fetal MRI. Sonographic abnormalities included ventricular dilatation (n=3), microcephaly (n=1), twin pregnancy with in utero death of a twin and suspected cerebral lesion in the surviving co-twin (n=3). MRI was performed with a 1.0 T unit using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences between 28 and 35 weeks of gestation. US and MRI images were compared with pathologic findings or postnatal imaging. MRI diagnosed hydranencephaly (n=1), porencephaly (n=2), multicystic encephalomalacia (n=2), unilateral capsular ischemia (n=1), corpus callosum and cerebral atrophy (n=1). In comparison with US, visualization of fetal brain anomalies was superior with MRI. The present cases demonstrate that MRI is a valuable complementary means of investigation when a brain pathology is discovered or suspected during prenatal US. Copyright © 2001 John Wiley & Sons, Ltd.     

Fetal ascites and oligohydramnios: Prenatal diagnosis of a sialic acid storage disease (index case)

In a 20-year-old primiparous patient, a routine ultrasound scan performed at 28 weeks revealed fetal ascites, bilateral talipes, and oligohydramnios. This woman, married to possibly her first cousin, was at risk for an autosomal recessive disease, a metabolic disorder. At 29 weeks, an amniotic fluid biochemical study revealed the presence of an abnormal band of free sialic acid, leading to a diagnosis of a congenital form of sialic acid storage disease. Termination of pregnancy was performed at 30 weeks. Measurement of free sialic acid in cultured fetal skin fibroblasts confirmed the diagnosis.     

Three-dimensional ultrasound in evaluating the fetus

In recent years three-dimensional (3D) ultrasound has made a place in clinical practice and has become a major field of research in obstetrics. In this article we will review the diagnostic performance of the most widely used 3D ultrasound applications in the assessment of fetal anomalies, explain the technique to gain correct 3D images and offer some practical advice for their efficient use. Examples are given to demonstrate the applicability and vividness of 3D in daily routine. Copyright © 2010 John Wiley & Sons, Ltd.