Fetal biometry of skeletal dysplasias: a multicentric study.

Abstract

Twenty‐three diagnostic centers worldwide contributed 127 cases of 17 skeletal dysplasias. Discriminant analysis showed that the femur length was the best biometric parameter to distinguish among the five most common disorders in this series (thanatophoric dysplasia, osteogenesis imperfecta type II, achondrogenesis, achondroplasia and hypochondroplasia). Fifty‐four percent of fetuses with femur length below 30% of the mean for gestational age had achondrogenesis. Seventy‐eight percent of measurements between 40 and 60% of the mean for gestational age represented either thanatophoric dysplasia or osteogenesis imperfecta type II. Fetuses who had over 80% of the mean for gestational age had predominantly hypochondroplasia, achondroplasia, and osteogenesis imperfecta type III.

Prenatal sonographic diagnosis of skeletal dysplasias

“…This study (n = 162) Sharony et al 16 (1993) (n = 172) Goncalves and Jeanty 20 (1994) (n = 139) Gaffney Values are given as n (%) for cases with true skeletal dysplasias. Goncalves and Jeanty 20 : 127 from multiple centers plus 12 from previous publications; Sharony et al 16 : 54 false-positives; Doray et al 15 16 , as exact numbers were not given by the authors). †Figures quoted in the text.…”

“…In ultrasound screening, the FL is the best parameter for the detection of skeletal dysplasias 20 . However, not all cases of skeletal dysplasia have shortening below −2 SD.…”

“…This can be seen particularly well in the Z-score plots, for example in the FL Z-score curves for TD and OI ( Figures S5 and S6 online). Thus we chose this approach over the one used in another large biometry study of fetal skeletal dysplasias, which grouped affected fetuses by percentages of the mean 20 .…”

Thanatophoric dysplasia: Role of 3‐dimensional sonography

“…10 For instance, aortic hypoplasia has been reported. 11 However, no associated anomaly was present in our series ( Table 1).…”

Evaluation of the Child with Short Stature

“…21 A powerful rule of thumb is that until proven otherwise, age-adjusted fetal femoral length of less than 40% indicates achondrogenesis, 40% to 60% is consistent with osteogenesis imperfecta type II or thanotophoric dysplasia, and greater than 80% of femoral length points to osteogenesis imperfecta type III or achondroplasia. 22,23 Additional prenatal cytogenetic and molecular genetic analysis may also be undertaken as indicated. 24 Situations where such studies are felt to be appropriate include a parent with a known skeletal dysplasia, significant family history, and micomelic or hypoplastic thorax ultrasound findings.…”