Second-trimester prenatal screening markers for Down syndrome in women with insulin-dependent diabetes mellitus

Published studies have shown that some serum markers used in screening for Down syndrome tend to be lower among women with insulin-dependent diabetes mellitus (IDDM). On this basis, many screening programmes adjust the marker levels to take account of this difference. Recent studies suggested that the marker levels were not different, and so adjustment may no longer be needed, possibly because of better diabetic control. Data from a prenatal screening programme for Down syndrome were examined to see whether the median values of second-trimester screening markers were still reduced in pregnant women with IDDM. A total of 366 women with IDDM singleton pregnancies without Down syndrome were identified from the screening programme at Barts from 1989 to 2002. After allowing for maternal weight, the median multiples of the median (MoM) for IDDM-unaffected singleton pregnancies were as follows: 0.88 (95% confidence interval 0.84–0.93) for alphafetoprotein (AFP), 0.95 (0.91–0.99) for unconjugated oestriol (uE₃), 0.90 (0.80–1.01) for total human chorionic gonadotrophin (total hCG), 0.98 (0.88–1.08) for free β-hCG, and 0.99 (0.89–1.10) for inhibin-A. The median levels for AFP and uE₃ were statistically significantly lower in pregnant women with IDDM. The other markers were not significantly different in women with and without IDDM. There remains a case for adjusting AFP and uE₃ levels in women with IDDM in prenatal screening programmes for Down syndrome. Copyright © 2004 John Wiley & Sons, Ltd.     

Prenatal diagnosis of Pierre–Robin sequence as part of Stickler syndrome

Stickler syndrome or hereditary progressive arthro-ophthalmopathy, is an autosomal dominant condition characterized by ocular manifestations, arthritic changes, orofacial features and deafness, in variable degrees. We report the first case of prenatal diagnosis of Stickler syndrome in a child with a Pierre–Robin sequence (PRS) causing a polyhydramnios. When isolated polyhydramnios is not explained by immunological, metabolic or infectious causes, swallowing difficulty due to PRS must be considered. As PRS is aetiologically heterogenous, the prognosis depends on the cause. Genetic investigations and familial history must be taken into account. Here, in a context of familial Stickler syndrome, making the prenatal diagnosis of PRS as part of Stickler syndrome allowed us to reassure the parents and to anticipate airway trouble at the child's birth. Copyright © 2002 John Wiley & Sons, Ltd.     

Use of dimethyl sulfoxide as solubilization agent in the detection of 2,3,7,8-TCDD by radioimmunoassay

Immunoassays are potentially valuable tools for use in screening environmental samples for a broad range of contaminants, such as polychlorinated dibenzo-p-dioxins (PCDDs). The performance of the radioimmunoassay (RIA) for PCDDs was characterized using 4 solubilization systems: Cutscum, Triton, horse serum, and dimethyl sulfoxide (DMSO). The DMSO based assay appeared to perform best at low 2,3,7,8-TCDD levels. The effects of assay incubation time and hapten storage conditions on the DMSO based assay were assessed. The separation of bound from unbound radioactivity was accelerated without adversely affecting assay performance. Further assay development through the use of an alternative labelled hapten is considered.     

Prenatal diagnosis of Mohr syndrome by ultrasonography

A case of prenatal diagnosis of Mohr syndrome is presented. The ultrasound examination was indicated by the previous birth of an affected brother. The need for genetic counselling is stressed, when polydactyly is observed accidentally at ultrasound examination during pregnancy.