ultrasound diagnosis of fatal anomalies

8 Skeletal Anomalies
General information
Self-Help Organization
Title: Little People of America (English/
Spanish)
Description: Provides mutual support to
people of short stature (4 feet 10 inches/1.5 m
and under) and their families. Information on
physical and developmental concerns, employment,
education, disability rights, medical
issues, adaptive devices, etc. Newsletter.
Provides educational scholarships and medical
assistance grants, access to medical advisory
board, assistance in adoption. Local, regional,
and national conferences and athletic
events. Online chat room.
Scope: National
Number of groups: 54 chapters
Founded: 1957
Address: P.O. Box 745, Lubbock, TX 79408,
United States
Telephone: 1–888-LPA-2001
E-mail: LPADataBase@juno.com
Web: http://www.lpaonline.org
Achondrogenesis
Definition: Fatal skeletal dysplasia with a
marked shortening of the torso and extremities
and a comparatively large head.
Incidence: 0.2–0.5/10 000 births.
Sex ratio: M:F=1:1.
Clinical history/genetics: Partly autosomal-recessive
inheritance. Autosomal-dominant inheritance
is also known (new mutations).
Teratogens: Not known.
Origin: In isolated cases, a defect in synthesis of
collagen type II has been proved.
Ultrasound findings: There are various forms of
achondrogenesis (type I and type II). Severe
shortening of the extremities,anarrow thorax and
reduced ossification of the vertebral column and
the skull are characteristic features. In some
cases, hygroma colli or fetal hydrops may also be
present. Thickening of the soft tissue of the arms is
typically seen. Ascites and fetal hydrops may also
develop. The abdomen and head are very large
compared to the chest and the limbs. In contrast
to osteogenesis imperfecta, the skull is not compressible,
and fractures of the long bones are not
a feature; fractures of the ribs may sometimes be
seen. The diagnosis is possible as early as
12 weeks of gestation, due to the appearance of a
thickened nuchal fold (nuchal swelling) and
skeletal malformations.
Clinical management: Molecular-genetic diagnosis,
further ultrasound screening including
fetal echocardiography. In cases of achondrogenesis,
cardiac anomalies are seen rarely in
comparison with other skeletal disorders. Radiographic
examination of the skeletal system leads
to further confirmation. Termination of pregnancy
has to be considered, as the outcome is
fatal. Management of the pregnancy and labor
should not be influenced by fetal distress.
Procedure after birth: As the fetus is not viable,
intensive medical interventions are not recommended.
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