Skeletal abnormalities in fetuses with Down's syndrome: a radiographic post-mortem study

Abstract

Three key skeletal signs were present in trisomic fetuses: brachycephaly, absence of nasal bone ossification, and hypoplasia of the middle phalanx of the fifth digit. All these signs are appropriate to prenatal US screening. When present, they fully justify determination of the fetal karyotype by amniocentesis.

Nasal bone and trisomy 21: prenatal ultrasound and postmortem morphohistological study

“…The postmortem sections reveal the anterior part of the orbitosphenoidal wing (small arrow) and to the side, the temporal wing (big arrow) from which the small and great sphenoid wings later develop. These morphohistological findings confirm that the anatomical explanation for agenesis/hypoplasia of the nasal bone in trisomy 21 fetuses might be a result of delayed maturation in the ossification center of the chondrocranium at the level of the nasal bone 6,7 .…”

Normative values of fetal nasal bone lengths of Turkish singleton pregnancies in the first trimester

“…Mean maternal age was 29.67±4.50 years and mean gestational age was 12.54±0.61 weeks. Median values of nasal bone lengths were 1.7, 1.9, and 2.2 mm for 11 [0][1][2][3][4][5][6] , 12 0-6 and 13 0-6 gestational weeks respectively. Nasal bone length (NBL) increased linearly with advancing gestational age and CRL.…”

“…Pregnancies with any detected/ suspicious anatomical or genetic fetal anomalies, biochemical abnormalities, increased nuchal translucency measurements, and pregnancies of artificial reproduction techniques were excluded from data analyses. Mean±standard deviation, median and percentile values of the length of nasal bone were calculated separately for 11 [0][1][2][3][4][5][6] , 12…”

“…Absence of nasal bone ossification is one of the key skeletal features of trisomy 21 (2). Thus, determination of absence or presence of nasal bone is being used in the fetal sonographic screening for trisomy 21 (3)(4)(5)(6)(7)(8).…”

Investigation of Bone Ratios for Prenatal Fetal Assessment in Taiwanese Population

“…Recently, fetal genetic ultrasound screening has been proposed as an additional screening tool for aneuploidy [2]. Down syndrome fetuses usually have facial abnormalities, with especially an absent fetal nasal bone (NB) or NB hypoplasia due to delayed NB ossification, which have been observed as a fetal sonographic soft marker of Down syndrome [3].…”