False-negative results of trisomy 21 on direct analysis on chorionic villus sampling

Saura, R.; Roux, D.; Maugey-Laulon, Brigitte; Taine, Laurence; Wen, Z. Q.; Vergnaud, A.; Horovitz, J.

doi:10.1002/(sici)1097-0223(199808)18:8<866::aid-pd358>3.0.co;2-7

Cited by 10 publications

(6 citation statements)

References 7 publications

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“…The false negative case was trisomy 18; this karyotype was prominent among false negative results in another study on CVS after the first trimester, where five of the nine false negatives had trisomy 18 8 . A recent publication describes three false negative results of trisomy 21 in 9000 first trimester direct tests 24 . From these data, it appears that it is necessary to use both the direct and culture preparation to obtain the most accurate prediction of the chromosome analysis.…”

Section: Discussionmentioning

confidence: 99%

Fetal karyotyping by chorionic villus sampling after the first trimester

Carroll

Davies

Kyle

et al. 1999

BJOG

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Objective To evaluate chorionic villus sampling (CVS) as a technique for karyotyping after the first trimester by examining the incidence of result failure, confined placental mosaicism, and false positive or negative results at different gestational ages.Methods During a nine year period between 1989 and 1997, all results of CVS between 8 and 37 weeks of gestation provided by the Regional Cytogenetics Centre were analysed retrospectively by examining indications for CVS, weights of tissue received, gestational age at sampling and karyotype results.Results There were 2424 chorionic villus samples analysed by the direct method andor cell culture. In 1548 cases CVS was performed before 14 weeks (Group l), in 685 between 15 and 20 weeks (Group 2), in 160 between 21 and 28 weeks (Group 3) and in 31 cases after 29 weeks (Group 4). Although there was a trend for an increasing rate of failed direct preparation results from Groups 1 to 4 which were 3.8%, 4.7%, 5.6% and 6.6%, respectively; these results were not significantly different. There were 19 cases of confined placental mosaicism and the incidence was significantly greater in Group 3 compared with Group 1 (P < 0.05), and in Groups 3 and 4 combined compared with Group 1. There were six false positive and one false negative result following direct analysis with no significant differences between gestational ages.Conclusions CVS is a useful test after the first trimester, especially when a fast result is clinically required. However, after 20 weeks, when cordocentesis is available, the higher rate of cytogenetic discordancy between the placenta and the fetus means that cordocentesis may be preferable. METHODSThere are numerous publications on chorionic villus sampling (CVS) in the first trimester14. Because the mitotic index of the placenta decreases with advancing gestation5, CVS after the first trimester has gained less widespread acceptance. This may be based partly on the belief that insufficient metaphases in the cytotrophoblast are available for analysis. There have been previous reports on the rates of failed results, confined placental mosaicism and false positive and negative results with CVS after the first trimester (Table l)"14. However, there are deficiencies in many of these studies including lack of analysis by gestational age, insufficient data on cell culture, relatively small patient numbers, and no examination of villus sample weights in relation to both gestational age and result. The purpose of our study was to address these deficiencies by evaluating cytogenetic aspects of CVS in the second and third trimester in relation to the first. Confined placental mosaicism (CPM) was classified into three types". CPM 1 was defined as the presence of two or more karyotypically different cell lines in the direct cytotrophoblast preparation but not in cultured chorionic cells, follow up amniotic fluid cells or fetal fibroblasts. CPM 2 refers to mosaicism in cultured cells but not in the direct preparation or follow up studies. CPM 3 is mosaicism present in...

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Section: Discussionmentioning

confidence: 99%

Fetal karyotyping by chorionic villus sampling after the first trimester

Carroll

Davies

Kyle

et al. 1999

BJOG

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“…Selection of villi was performed macroscopically in the laboratory from 1996 to 1997. However, some cases of massive MCC led us to select them carefully by microscopy after 1998 (Saura et al, 1998). Maternal cell contamination (MCC) was classified as light (<10% of examined cells), moderate (10-50% of examined cells), great (>50% of examined cells) and total (100% of examined cells).…”

Section: Methodsmentioning

confidence: 99%

Feasibility, accuracy and safety of chorionic villus sampling: a report of 10 741 cases

et al. 2003

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“…Sikkema-Raddatz et al (1997) reviewed 20 published cases of discrepant karyotypes (excluding structural abnormalities) where direct karyotypes gave a 'false negative' normal result of which eight involved trisomy 21. Saura et al (1998) reported three cases of false negative trisomy 21 in 'Direct' preparations in 9000 CVS and thus estimated the risk of recurrence of false negative trisomy 21 in 'Direct' preparations at 1 : 3000. Kalousek (1989) proposed that trisomy 21 zygotes may be particularly likely to show cell lineagespecific non-disjunction in the cytotrophoblast layer as a result of the rapid expansion of this cellular compartment during the first trimester.…”

Section: Significance Of Absence Of Triallelic Allele For Chromosome mentioning

confidence: 99%

“…Mosaicism may be compartmentalised within a cell lineage and may or may not be associated with a normal fetal karyotype (Kalousek et al, 1987;Simoni and Sirchia, 1994). For trisomy 21, false negative results are more prevalent in direct or short-term culture (STC), consistent with the absence of trisomic cells from the embryologically remote cytotrophoblast layer (Sikkema-Raddatz et al, 1997;Saura et al, 1998). For non-mosaic standard trisomy 13, 18 and 21, long-term culture (LTC) karyotypes are considered a reliable indicator of fetal abnormality (Smith et al, 1999).…”

Section: Introductionmentioning

confidence: 99%