Prenatal diagnosis of an isochromosome 5p in a fetus with increased nuchal translucency thickness and pulmonary atresia with hypoplastic right heart at 14 weeks

We report on a fetus presenting with increased nuchal translucency at 11 weeks' gestation, suggesting cystic hygroma. Chorion villous sampling was performed, and cytogenetic analysis revealed a supernumerary isochromosome 5p leading to tetrasomy 5p: 47,XX,+ i(5p)[7]/46,XX[5] after short-term culture and 47,XX,+ i(5p)[20] after long-term culture. Subsequent targeted sonographic follow-up at 12 and 14 weeks revealed further increase of the NT to 6.4 mm and the additional presence of a congenital heart defect (pulmonary atresia with intact ventricular septum). Termination of pregnancy was performed, and the heart defect was confirmed. Isochromosome 5p was found in varying proportions in all examined organs. Only a few cases of mosaic tetrasomy 5p have been reported in the literature, and recent reports on prenatally detected isochromosome 5p showed a possible relationship to increased nuchal translucency in some cases and also a possible role of confined mosaicism in others. Whereas cases with confined mosaicism did not show suspicious signs on ultrasound, true mosaicism conversely showed increased nuchal thickness as well as structural abnormalities. This is the first report on the association of a cardiac defect with this chromosome aberration. Copyright © 2004 John Wiley & Sons, Ltd.     

Karyotype abnormalities in fetuses diagnosed as abnormal on ultrasound before 20 weeks' gestational age

This study examined rates of karyotype abnormalities in fetuses diagnosed by ultrasound as abnormal before 20 weeks' gestational age and which prompted a follow-up amniocentesis or chorionic villus sampling. Those diagnosed before 20 weeks were compared with those diagnosed at or after 20 weeks. A retrospective study identified ultrasonographically abnormal fetuses in whom karyotyping had been undertaken, 306 fetuses before 20 weeks' gestational age and 241 after. Isolated malformations before 20 weeks had, on average, an 18 per cent risk of karyotype abnormality, compared with 20 per cent later. Specific rates were calculated; for example, heart abnormality was associated with karyotype abnormality in 7 per cent of cases before 20 weeks and in 14 per cent later. Multiple malformations and karyotype abnormalities were found together in 28 per cent of fetuses prior to 20 weeks and in 33 per cent of the older fetuses. Specific associations included nuchal oedema and trisomy 21 in 21 per cent of fetuses before 20 weeks. No karyotype abnormalities were found in fetuses diagnosed with choroid plexus cysts. An overview of trisomies in Victoria, in 1991, showed that 50 per cent of trisomy 18, 42 per cent of trisomy 13, and 9·5 per cent of trisomy 21 cases were identified by ultrasound in women less than 37 years of age. Another 28·6 per cent of trisomy 21 fetuses were detected in women of advanced maternal age who underwent amniocentesis or chorionic villus sampling, making a total of 38·1 per cent of trisomy 21 that were detected prenatally. The importance of early karyotyping specifically relates to the ongoing management of the pregnancy if the chromosomes are normal, and facilitates decision-making regarding termination of pregnancy if the chromosomes are abnormal.     

煤沥青烟气对职业接触人群姐妹染色单体交换的影响

利用姐妹染色单体交换率（ＳＣＥ）的增加与否，作为细胞遗传毒理学的指标来评价一些理化因子的诱变性，是检测化学致突的方法之一，通过对某碳素厂接触生产性煤焦沥青烟气的工人人体外周血淋巴细胞ＳＣＥ观察表明，车间接触组工人ＳＣＥ明显高于非接触组工人（约１．６７倍）；在接触线组中，在者ＳＣＥ高于非吸烟者；同为吸烟者，接触组工人ＳＣＥ高于非接触组工人（约１．４８倍）。结果提示示煤焦沥青烟尘能引起工人ＳＣＥ的改变     

Early prenatal diagnosis of ventricular diverticulum complicated by serous pericardial effusion

An unusual case of apical diverticulum complicated by serous pericardial effusion and diagnosed ultrasonographically at 13 weeks of gestation is described. A therapeutic abortion was induced at 14 weeks and the complete post-mortem examination did not show additional malformation. Cardiac diverticulum is a rare malformation that occurs as an isolated defect or as part of a complex midline thoraco-abdominal defect. Only two prenatally diagnosed cases have been previously reported in the literature and none with associated hydropericardium.     

Abnormal pregnancy sonogram and chromosomal anomalies: Four years' experience with rapid karyotyping

Over a four-year period, 140 pregnancies with different malformations detected by ultrasound were examined cytogenetically. Gestational age ranged from 13 to 36 weeks. Twenty-six fetuses (18.6 per cent) had abnormal karyotypes, including trisomies, triploidy, monosomy X, and structural anomalies. Similar malformations were found in fetuses with different chromosomal anomalies, indicating that the types of malformations are not specific for particular chromosomal anomalies. Chromosomal analysis was performed on amniotic fluid culture and by direct karyotyping of placental biopsies. Direct karyotyping is suggested to be the most rapid approach, especially if sonographic anomalies are detected close to the 24th week of gestation, shortly before delivery, and in cases of significant oligohydramnios.     

Umbilical and uterine flow velocity waveforms in pregnancies complicated by major fetal anomalies

A continuous wave Doppler unit was used to obtain umbilical and uterine artery flow velocity waveforms in pregnancies complicated by a major fetal abnormality. A total of 139 examinations were performed on 32 women between 26 to 41 weeks' gestation, and the records were reviewed to determine the changes associated with fetal malformation. The systolic/diastolic (A/B) ratio was used as an index of blood flow resistance in the umbilical artery and the systolic minus diastolic divided by systolic (A–B)/A for the branches of the uterine artery. Seventeen out of 32 patients showed high systolic/diastolic ratio in waveforms taken from the umbilical artery. In 30 out of 32 patients the uterine artery waveform was normal (in two patients the results were equivocal). It appears that a fetal mechanism may determine the changes in the umbilical placental circulation resulting in an umbilical artery pattern of high flow resistance in more than half of the patients with congenital anomalies.     

Prenatal diagnosis of del(11)(p13p15)

Prenatal diagnosis of del(11)(p13p15) was made on cultured amniotic fluid cells and confirmed on fetal skin fibroblasts after termination of pregnancy. Both irides appeared behind schedule in development by 2–3 weeks in reference to the gestational age of the fetus. It is suggested that the aniridia of the aniridia-Wilms tumour association is due to developmental arrest. Confirmation of this complex is difficult at mid-gestation without critical pathological study of the eyes.     

Methods for prenatal assessment of fetal cardiac function

Fetal cardiac function is increasingly recognized as a marker of disease severity and prognosis in selected fetal conditions. Magnetic resonance imaging (MRI) has been used in experimental (animal) fetal cardiology but the lack of a noninvasive fetal electrocardiogram (ECG) to trigger image acquisition remains a major limiting factor precluding its application in humans. Fetal medicine specialists are therefore limited to ultrasound to evaluate human fetal cardiac function. In this review, we aim to provide a complete overview of the different ultrasound techniques that can be used for fetal cardiac function assessment and we discuss their (theoretical) strengths and shortcomings. Conventional methods include M-mode assessment of ventricular contractility and Doppler assessment of the precordial veins and cardiac output (CO). More recent techniques such as the measurement of the myocardial performance index (MPI), myocardial motion analysis with tissue Doppler, speckle tracking and three-dimensional (3D) ultrasound techniques are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.