Clinical websites are currently dangerous to health.

The Internet is becoming a ubiquitous medium, open to all. The paper explores the reasons why current health-related websites require extensive review and investment to ensure that they address the full spectrum of the audiences who may access their site. The audiences are no longer purely local or even solely those who work in the health domain. They will include everyone, from professional healthcare practitioners to members of the general public. The site web masters should also consider the range of purposes for which these disparate groups access the site. The language, content intensity and presentation should have a different style and be identified by its intended audience to avoid a range of problems including mis-interpretation, mis-targetting of content, mis-representation of source and quality. Inappropriate content and presentation could jeopardise the credibility of health sites, and thus healthcare provision, with the newly emerging audiences. Recent studies involving the evaluation of many web sites have assessed their 'fitness for purpose' as information repositories for different audiences. The criteria by which clinically related web contents are judged will vary, depending on the type of visitor to the site. Formal qualification of web content is ongoing--addressing both structured definition [1] and quality criteria [2]. Originators of web material should consider the full spectrum of the audiences who may access their site, from professional healthcare practitioners to members of the general public, and the purposes for which they access the site. The language, content intensity and presentation should have a different style and be identified by its intended audience to avoid a range of problems including mis-interpretation, mis-targetting of content, mis-representation of source and quality.

Cytogenetic results from the U.S. Collaborative Study on CVS.

Cytogenetic data are presented for 11,473 chorionic villus sampling (CVS) procedures from nine centres in the U.S. NICHD collaborative study. A successful cytogenetic diagnosis was obtained in 99.7 per cent of cases, with data obtained from the direct method only (26 per cent), culture method only (42 per cent), or a combination of both (32 per cent). A total of 1.1 per cent of patients had a second CVS or amniocentesis procedure for reasons related to the cytogenetic diagnostic procedure, including laboratory failures (27 cases), maternal cell contamination (4 cases), or mosaic or ambiguous cytogenetic results (98 cases). There were no diagnostic errors involving trisomies for chromosomes 21, 18, and 13. For sex chromosome aneuploidies, one patient terminated her pregnancy on the basis of non-mosaic 47,XXX in the direct method prior to the availability of results from cultured cells. Subsequent analysis of the CVS cultures and fetal tissues showed only normal female cells. Other false-positive predictions involving non-mosaic aneuploidies (n = 13) were observed in the direct or culture method, but these cases involved rare aneuploidies: four cases of tetraploidy, two cases of trisomy 7, and one case each of trisomies 3, 8, 11, 15, 16, 20, and 22. This indicates that rare aneuploidies observed in the direct or culture method should be subjected to follow-up by amniocentesis. Two cases of unbalanced structural abnormalities detected in the direct method were not confirmed in cultured CVS or amniotic fluid. In addition, one structural rearrangement was misinterpreted as unbalanced from the direct method, leading to pregnancy termination prior to results from cultured cells showing a balanced, inherited translocation. False-negative results (n = 8) were observed only in the direct method, including one non-mosaic fetal abnormality (trisomy 18) detected by the culture method and seven cases of fetal mosaicism (all detected by the culture method). Mosaicism was observed in 0.8 per cent of all cases, while pseudomosaicism (including single trisomic cells) was observed in 1.6 per cent of cases. Mosaicism was observed with equal frequency in the direct and culture methods, but was confirmed as fetal mosaicism more often in cases from the culture method (24 per cent) than in cases from the direct method (10 per cent). The overall rate of maternal cell contamination was 1.8 per cent for the culture method, but there was only one case of incorrect sex prediction due to complete maternal cell contamination which resulted in the birth of a normal male.(ABSTRACT TRUNCATED AT 400 WORDS)

Patterns of mood states in pregnant women undergoing chorionic villus sampling or amniocentesis.

The purpose of this study was to compare patterns of self-reported mood states of women having chorionic villus sampling (CVS) (n = 151) to those of women electing amniocentesis (n = 30) with the indication of advanced maternal age. Mood states were defined as scores on the 6 subscales of the Profile of Mood States (POMS). Women at 4 U.S. prenatal diagnostic facilities completed the POMS at 4 assessment periods. These were a) at their initial genetic counseling session, b) 2 weeks post CVS results (or an equivalent time), c) 2 weeks post amniocentesis results (or an equivalent time), and d) at 30 weeks gestation. Repeated measures analysis of variance revealed that anxiety, fatigue, and confusion decreased, and vigor increased in both groups as the pregnancy progressed. Depression decreased in both groups and then increased at assessment 4 in women in the amniocentesis group but not in those electing CVS. Results should be interpreted in conjunction with obstetrically and genetically-oriented findings regarding safety and accuracy to help women decide between the 2 procedures.

Fetal blood sampling demonstrating chimerism in monozygotic twins discordant for sex and tissue karyotype (46,XY and 45,X)

Fetal blood sampling has been used in the genetic work-up of twin gestations for rapid karyotyping. We present a case of twins which on ultrasound evaluation revealed hydrops fetalis in one twin and a normal second twin. Fetal blood sampling revealed the presence of mosaicism for 46,XY/45,X in both twins. HLA antigen testing showed the twins to be identical. The patient elected pregnancy termination. Blood chromosomal analysis after delivery revealed both twins to have 46,XY/45,X mosaicism, but the twin with signs of hydrops fetalis had tissue chromosomes of 45,X and the normal twin had tissue chromosomes of 46,XY. Amniotic fluid chromosomal analysis revealed 46,XY in twin A and 45,X in twin B. This represents a case of identical (monozygotic) twins with sex discordance. In this case, there was the probable occurrence of post-zygotic chromosomal non-disjunction leading to the discordancy of the sex in this set of twins. With the presence of vascular communication in monozygotic twins, there is the possibility of exchange of blood in monozygotic twins and the result of blood chimerism in twins.

Integration of the transabdominal technique into an ongoing chorionic villus sampling program.

Data are presented on 869 patients undergoing chorionic villus sampling procedures by one of two sampling techniques: 544 by a transcervical catheter aspiration method and 325 by a transabdominal two-needle aspiration method. The transcervical approach was the only procedure used in the first 330 cases, at which time the transabdominal technique was incorporated into our program. After an initial learning curve in the first 100 procedures the transcervical fetal loss rate stabilized at 2.7%, the number of patients requiring more than one catheter insertion decreased to 11%, and tissue weights greater than or equal to 10 mg were obtained in 88% of cases. The fetal loss rate for transabdominal chorionic villus sampling was 2.6%, indicating the addition of this new method did not significantly alter the fetal loss rate. Transabdominal chorionic villus sampling had an overall success rate of 99%, with only one insertion of the guide needle required for 98% of patients. Tissue weights of greater than or equal to 10 mg were obtained in 99% of cases. These results demonstrate that the transabdominal procedure can be rapidly and effectively incorporated by an operator already experienced with transcervical chorionic villus sampling. Since several contraindications exist for either chorionic villus sampling method, the availability of both techniques at a single center greatly enhances the ability to offer first-trimester fetal diagnosis to a majority of patients.

Prenatal diagnosis of haemophilia A by factor VIII gene analysis.

Cloned factor VIII deoxyribose nucleic acid (DNA) sequences were used as probes in the prenatal diagnosis of haemophilia A. Fetal DNA from cultured amniotic fluid cells was examined for a DNA polymorphism within the factor VIII gene which marked the haemophilia A gene in the pregnant obligate carrier. The fetus was predicted to be an affected male, and the diagnosis of haemophilia A was confirmed both in utero and after termination of the pregnancy.