Risk of fetal mosaicism when placental mosaicism is diagnosed by chorionic villus sampling


      OBJECTIVE: Our purpose was to determine the risk of fetal mosaicism when placental mosaicism is found on chorionic villus sampling. STUDY DESIGN: We present a case of mosaic trisomy 22 detected on chorionic villus sampling and subsequently found in the fetus. A review of comprehensive chorionic villus sampling studies with emphasis on follow-up for fetal mosaicism was conducted. RESULTS: Among 13 studies reviewed, 469 cases of placental mosaicism are presented; fetal mosaicism was found in 50 (10.7%). Factors associated with fetal mosaicism are (1) mosaicism on mesenchymal core culture and (2) type of chromosome abnormality involved - specifically, marker chromosomes (26.7%) and common autosomal trisomies (19.0%). Amniocentesis predicted fetal genotype in 93% to 100% of cases of placental mosaicism, depending on the cell type in which mosaicism was diagnosed. CONCLUSIONS: Although mosaicism is usually confined to the placenta, the fetus is involved in about 10% cases. Patients should be counseled about this risk and the accuracy of follow-up amniocentesis. (AM J OBSTET GYNECOL 1996;174:850-5.)


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Ledbetter DH
        • Zachary JM
        • Simpson JL
        • et al.
        Cytogenetic results from the U.S. collaborative study on CVS.
        Prenat Diagn. 1992; 12: 317-345
        • Association of Clinical Cytogenetic Working Party on Chorionic Villi in Prenatal Diagnosis
        Cytogenetic analysis of chorionic villi for prenatal diagnosis: an ACC collaborative study of U.K. data.
        Prenat Diagn. 1994; 14: 363-379
        • Wang BBT
        • Rubin CH
        • Williams J
        Mosaicism in chorionic villus sampling: an analysis of incidence and chromosome involved in 2612 consecutive cases.
        Prenat Diagn. 1993; 13: 179-190
        • Wolstenholme J
        • Rooney DE
        • Davison EV
        Confined placental mosaicism, IUGR, and adverse pregnancy outcome: a controlled retrospective U.K. collaborative survey.
        Prenat Diagn. 1994; 14: 345-361
        • Roland B
        • Lynch L
        • Berkowitz G
        • Zinberg R
        Confined placental mosaicism in CVS and pregnancy outcome.
        Prenat Diagn. 1994; 14: 589-593
        • Smidt-Jensen S
        • Lind A
        • Permin M
        • Zachary JM
        • Lundsteen C
        • Philip J
        Cytogenetic analysis of 2928 CVS samples and 1075 amniocenteses from randomized studies.
        Prenat Diagn. 1993; 13: 723-740
        • Miny P
        • Hammer P
        • Gerlach B
        • et al.
        Mosaicism and the accuracy of prenatal cytogenetic diagnoses after chorionic villus sample.
        Prenat Diagn. 1991; 11: 581-589
        • Fryburg JS
        • Dimaio MS
        • Yang-Feng TL
        • Mahoney MJ
        Follow-up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling.
        Prenat Diagn. 1993; 13: 481-494
        • Medical Research Council Working
        Party on the Evaluation of Chorionic Villus Sampling. Medical Research Council European trial of chorionic villus sampling.
        Lancet. 1991; 337: 1491-1499
        • Callen DF
        • Korban G
        • Dawson G
        • et al.
        Extra embryonic/fetal karyotypic discordance during diagnostic chorionic villus sampling.
        Prenat Diagn. 1988; 8: 453-460
        • Hogge WA
        • Schonberg SA
        • Golbus MS
        Chorionic villus sampling: experience of the first 1000 cases.
        AM J OBSTET GYNECOL. 1986; 154: 1249-1252
        • Teshima IE
        • Kalousek DK
        • Vekemans MJJ
        • et al.
        Chromosome mosaicism in CVS and amniocentesis samples.
        Prenat Diagn. 1992; 12: 443-459
        • Vejerslev LO
        • Mikkelsen M
        The European collaborative study on mosaicism in chorionic villus sampling: data from 1986 to 1987.
        Prenat Diagn. 1989; 9: 575-588
        • Tharapel AT
        • Elias S
        • Shulman LP
        • Seely L
        • Emerson DS
        • Simpson JL
        Resorbed co-twin as an explanation for discrepant chorionic villus results: non-mosaic 47,XX+16 in villi (direct and culture) with normal (46,XX) amniotic fluid and neonatal blood.
        Prenat Diagn. 1989; 9: 467-472
        • Crane JP
        • Cheung SW
        An embryogenic model to explain cytogenetic inconsistencies observed in chorionic villus versus fetal tissue.
        Prenat Diagn. 1988; 8: 119-129
        • Robinson WP
        • Inkert F
        • Bernasconi F
        • Lorda-Sanchez I
        • Werder EA
        • Schinzel AA
        Molecular studies of chromosomal mosaicism: relative frequency of chromosome gain or loss and possible role of cell selection.
        Am J Hum Genet. 1995; 56: 444-451
        • Kalousek DK
        The role of confined placental mosaicism in placental function and human development.
        Growth Genet Hormones. 1988; 4: 1-3
        • Johnson A
        • Wapner RJ
        • Davis GH
        • Jackson LG
        Mosaicism in chorionic villus sampling: an association with poor perinatal outcome.
        Obstet Gynecol. 1990; 75: 573-577
        • Stioui S
        • De Silestris M
        • Molinari A
        • Stripparo L
        • Ghisoni L
        • Simoni G
        Trisomic 22 placenta in a case of severe intrauterine growth retardation.
        Prenat Diagn. 1989; 9: 673-676
        • Wapner RJ
        • Simpson JL
        • Golbus MS
        • et al.
        Chorionic mosaicism association with fetal loss but not with adverse perinatal outcome.
        Prenat Diagn. 1992; 12: 347-355
        • Schinzel AA
        • Basaran S
        • Bernasconi F
        • Karaman B
        • Yuksel-Apak M
        • Robinson WP
        Maternal parental disomy 22 has no impact on the phenotype.
        Am J Hum Genet. 1994; 54: 21-24
        • Hsu LYS
        Prenatal diagnosis of chromosomal abnormalities through amniocentesis.
        in: Genetic disorders and the fetus. : Johns Hopkins University Press, Baltimore1992
        • Schuring-Blom GM
        • Keijzer M
        • Jakobs ME
        • et al.
        Molecular cytogenetic analysis of term placentae suspected of mosaicism using fluorescence in situ hybridization.
        Prenat Diagn. 1993; 13: 671-679
        • Brondum-Nielsen K
        • Mikkelsen M
        A 10-year survey, 1980-1990, of prenatally diagnosed small supernumerary marker chromosomes, identified by FISH analysis: outcome and follow-up of 14 cases diagnosed in a series of 12,699 prenatal samples.
        Prenat Diagn. 1995; 15: 615-619