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Tesi etd-06172017-124204

Thesis type
Tesi di specializzazione (5 anni)
In utero ultrasound diagnosis of fetal extremity anomalies
Corso di studi
relatore Prof.ssa Strigini, Francesca Anna Letizia
Parole chiave
  • fetal ultrasonography
  • clubfoot
  • prenatal diagnosis
  • ultrasound
  • fetal extremities
Data inizio appello
Data di rilascio
Riassunto analitico
Limb anomalies are often missed on prenatal sonography, and this is
particularly true with regard to hand or foot defects. It is well known that
phalange anomalies can be extremely difficult to diagnose in utero. In a large
number of cases these abnormalities are isolated, but they can be frequently
associated with other fetal anomalies, for example malformations or
chromosomal disorders.
The aim of the present study was to evaluate the accuracy of targeted
sonography in detecting and describing limb defects.
We reviewed 80 consecutive pre- and / or post- natal diagnoses of fetal /
neonatal deformities of the extremities in pregnant women who had received
an ultrasound scan in the referral center of the University of Pisa between
January 2002 and May 2017. All cases were reviewed by the clinical geneticist,
in order to obtain the appropriate diagnosis selecting the correct genetical tests.
More than half of the limb anomalies were represented by abnormal limb
attitude (47 out of 80). In 41 fetuses the abnormal limb attitude was represented
by clubfoot / feet, whereas 6 showed an abnormal attitude of all four
extremities without any structural or bony malformation.
At neonatal or post-mortem examination, 6 fetuses showed agenesis of one
hand (n=5) or both feet (n=1). The remaining cases consisted of various types
of finger or toe malformations, such as polydactyly (n=7), syndactyly (n=2) or
finger / toe agenesis(n=4), which were for the most part combined together,
and were grouped in the present study as “complex” anomalies (n=13).
Overall, limb anomalies affected only the feet more frequently than only the
hands (47 vs 16, p < 0.0001); most of them were clubfoot (n=41), associated
with neural tube defects in 8 fetuses. Foot anomalies were bilateral more
frequently than hand anomalies (26 / 47 vs 4 / 16; p < 0.0001).
Hands and feet were concurrently involved in 16 cases, which mainly consisted
in abnormal attitude (6 cases, all forms of arthrogryposis), or “complex” (8
A syndromic form was diagnosed in 21 fetuses, out of which 9 had a
chromosomal anomaly, and 6 cases received a specific diagnosis confirmed by
molecular biology. Fetuses with anomalies of both upper and lower extremities
had a syndrome more often than fetuses with anomalies of only feet or only
hands (11 / 16 vs 10 / 63, p < 0.0001).
Ultrasonographic sensitivity for anomalies of fetal extremities was 79.7%, with
a positive predictive value of 98%; the only false positive result was a
diagnosis of clubfoot in a fetus spontaneously miscarried at 15 weeks of
gestation. On the whole, sonographic anomalies were correctly recognised in
90.5% of fetuses that resulted to have a syndrome at genetic tests, while in nonsyndromic
fetuses the percentage of identification was 71.2%.
However, the sensitivity varied according to the different anomalies:
ultrasound detection was 36 / 41 for clubfoot, 5 / 6 for arthrogryposis, and 6 /
6 for agenesis of the whole extremity. By contrast, 4 cases out of 13 in the
group of “complex” anomalies eluded ultrasound prenatal diagnosis.