Prospective ranking of the sonographic markers for aneuploidy: Data of 2143 prenatal cytogenetic diagnoses referred for abnormalities on ultrasound

Abstract

It is suggested this data could be used to assist pre-procedural counselling of patients after the ultrasound scan in tertiary referral centres for prenatal cytogenetic diagnosis.

Should determination of the karyotype be systematic for all malformations detected by obstetrical ultrasound?

“…Hydrops and cystic hygroma have the highest and statistically significant rate of chromosomal abnormalities (p < 0.001), this corresponds to previous reports (Van Zalen-Sprock et al, 1991;Gonen et al, 1995;Wladimiroff et al, 1995). In our series, other specific malformations that were associated with a and 12% of omphalocele with T18 (Chen et al, 1996;Wilson et al, 1992;Halliday et al, 1994;Eurin et al, 1999;Daniel et al, 2003). The rate of chromosomal abnormalities described in the literature in case of isolated central nervous system and cardiovascular malformations is even higher than in our results, 20% (Ott and Taysi, 2001) and between 15 and 23% (Friedman et al, 1993;Ott and Taysi, 2001) respectively.…”

“…Furthermore, the incidence of chromosomal anomalies may vary according to the presence of multiple or isolated malformations as well as the type of malformation. The increased risk in fetuses with abnormal karyotype between multiple malformations and isolated malformations has been suggested in several studies (Nicolaides et al, 1992b;Snijders et al, 1996;Daniel et al, 2003). Yet, the incidence of chromosomal abnormalities in low risk pregnancies in which fetal malformations have been diagnosed by obstetrical ultrasonography has not been widely studied (Tabor and Philip, 1987;Bellotti et al, 1998;Drummond et al, 2003).…”

From Karyotyping to Array-CGH in Prenatal Diagnosis

“…The extensive experience with karyotyping in pregnancies with fetal ultrasound anomalies has yielded figures which can be applied in clinical practice when counseling parents of a fetus with ultrasound anomalies. For many specific structural anomalies the likelihood that a chromosomal anomaly will be detected with karyotyping is known [Daniel et al, 2003;Wimalasundera and Gardiner, 2004;Carbone et al, 2011]. The a priori probability that array-CGH will detect a pathogenic aberration per fetal structural anomaly, or per combination of anomalies, is not yet known [Machado et al, 2011].…”

“…The chance of detecting a chromosomal anomaly depends on the type and combination of fetal anomalies, and on the gestational age [Wilson et al, 1992;Rizzo et al, 1996;Daniel et al, 2003]. Because of its increased resolution, array-CGH or SNP array has a greater yield in these high risk pregnancies.…”

Changing paradigm in prenatal management

“…These could further improve the effi ciency of Down syndrome screening. [4] The early scan also provides reliable identifi cation of chorionicity, which is the main determinant of multiple pregnancy outcomes.…”