ultrasound diagnosis of fatal anomalies

SKELETAL ANOMALIES
Prognosis: Intrauterine fetal death usually occurs,
resulting in stillbirth; if not, then death occurs
within 24 h after birth due to hypoplasia of
the lungs.
References
Benacerraf B, Osathanondh R, Bieber FR. Achondrogenesis
type l: ultrasound diagnosis in utero. JCU J Clin Ultrasound
1984; 12: 357–9.
Gabrielli S, Falco P, Pilu G, Perolo A, Milano V, Bovicelli L.
Can transvaginal fetal biometry be considered a useful
tool for early detection of skeletal dysplasias in
high-risk patients? Ultrasound Obstet Gynecol
1999;13 : 107–11.
Glenn LW, Teng SS. In utero sonographic diagnosis of
achondrogenesis. JCU J Clin Ultrasound 1985; 13:
195–8.
Johnson VP, Yiu CV, Wierda DR, Holzwarth DR. Midtrimester
prenatal diagnosis of achondrogenesis. J
Ultrasound Med 1984; 3: 223–6.
Mahony BS, Filly RA, Cooperberg PL. Antenatal sonographic
diagnosis of achondrogenesis. J Ultrasound
Med 1984; 3: 333–5.
Ozeren S, Yüksel A, Tom T. Prenatal sonographic diagnosis
of type I achondrogenesis with a large cystic hygroma
[letter]. Ultrasound Obstet Gynecol 1999; 13:
75–6.
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[Lethal osteochondrodysplasias: prenatal and postnatal
differential diagnosis; in German.] Ultraschall
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Soothill PW, Vuthiwong C, Rees H. Achondrogenesis
type 2 diagnosed by transvaginal ultrasound at
12 weeks’ gestation. Prenat Diagn 1993; 13: 523–8.
Tongsong T, Srisomboon J, Sudasna J. Prenatal diagnosis
of Langer–Saldino achondrogenesis. J Clin Ultrasound
1995; 23: 56–8.
Wenstrom KD, Williamson RA, Hoover WW, Grant
SS. Achondrogenesis type II (Langer–Saldino) in association
with jugular lymphatic obstruction
sequence. Prenat Diagn 1989; 9: 527–32.
Won HS, Yoo HK, Lee PR, et al. A case of achondrogenesis
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Achondroplasia
Definition: This is the most frequent heterozygous,
nonfatal type of skeletal dysplasia (the homozygous
form is fatal), with severe shortening
of the limbs and a large head (dwarfism). Adult
height: 116–140 cm.
Incidence: 0.5–1.5 per 10 000 births.
Sex ratio: M:F=1:1.
Clinical history/genetics: Autosomal-dominant
inheritance. New mutations are seen in 80%. Affected
gene: FGFR3, gene locus: 4 p16.3.
Teratogens: Not known.
Pathogenesis: Reduced chondral ossification.
Mutation of the fibroblast growth factor receptor.
In the homozygous form, early manifestation
and fatal outcome. In the heterozygous form, a
normal ultrasound appearance is possible up to
20 weeks.
Ultrasound findings: Disproportionate hyposomia
(dwarfism) with short limbs, large head,
and a typical facial profile—protruding forehead
(also known as frontal bossing) and flattened
nasal bridge. The shortening of the bones of the
extremities is apparent in the second half of
pregnancy. The measurement of the long bones
lies well below the fifth percentile, with accentuation
of the proximal part. The hands and feet
appear short and stubby. Hydramnios develops
in the last trimester. The diagnosis is made with
certainty after 24 weeks of gestation, the most
reliable quotient being femur length to biparietal
diameter, as the femur is often only minimally
shortened, but the head is typically very
large (macrocrania). In some cases, ventriculomegaly
is also observed.
Differential diagnosis: Asymmetrical growth restriction,
trisomy 21, hypochondroplasia, Kniest
syndrome, Russell–Silver syndrome, Shprintzen
syndrome, spondyloepiphyseal dysplasia,
Turner syndrome.
Clinical management: Further ultrasound
screening including fetal echocardiography,
karyotyping, molecular-genetic diagnosis. There
is a danger of cervical column compression due
to narrowing of the foramen magnum. Thus, any
clinical intervention that may cause manipulation
in the neck region during labor and delivery,
such as forceps or vacuum extraction, poses a
high risk of complications. For this reason, a cesarean
section may be an option for delivery.
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