Follow‐up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling

Abstract

Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated.

Trisomy 16 and trisomy 16 mosaicism: A review

“…Although additional data appeared to support the hypothesis [Kalousek and Vekemans, 1996], other investigators have failed to demonstrate a clear association between CPM and poor pregnancy outcome [Schwinger et al, 1989;Wapner et al, 1992;Fryburg et al, 1993;Kennerknecht et al, 1993;Roland et al, 1994;Wolstenholme et al, 1994;Goldberg and Wohlford, 1997]. A problem with all studies is the combination of diverse karyotypes (and different origins for trisomies), not all of which should necessarily be expected to have an equally detrimental effect on placental function.…”

Prenatal Detection of Two Different Monosomic Cell Lines by Chorionic Villus Sampling

“…Mosaicism is not a rare finding in CVS studies; when it is detected, serious problems in interpretation are raised (Wirtz et al, 1991;Simoni and Fraccaro, 1992;Fryberg et al, 1993). In the recently reported United Kingdom collaborative study of 7595 CVS cases, mosaicism was detected in 88 (1.16 per cent) and of these, only nine were confirmed in the fetus/liveborn while 53 were considered false positives (not confirmed on the fetus/ liveborn).…”

Early Filtration Amniocentesis for Further Investigation of Mosaicism Diagnosed by Chorionic Villus Sampling

“…CPM has in several publications been described to be associated with intrauterine growth retardation (IUGR) (Kalousek et al, 1991;Kennerknecht and Terinde, 1990;Fryburg et al, 1992), but follow-up studies of pregnancies with CVS mosaicism have failed to demonstrate this severe condition as a major problem (Wapner et al, 1992;Wolstenholme et al, 1994). The vast majority of reported cases have been infants of normal birth weight, though an association with higher rates of fetal loss has been described (Breed et al, 1991;Wapner et al, 1992).…”