Diagnostic ultrasound ( PDFDrive )

CHAPTER
33
The Fetal Face and Neck
Ana P. Lourenco and Judy A. Estroff
SUMMARY KEY POINTS
• Ear and eye anomalies often accompany abnormalities of
the skull and face.
• Abnormalities of fetal head size and shape may be
associated with various syndromes and chromosomal
anomalies.
• Hypoplastic or absent nasal bone may be seen in fetuses
with trisomy 21.
• Cleft lip may be associated with cleft palate, and detailed
description of the cleft is important to accurately counsel
parents, predict postnatal outcome, and anticipate type of
treatment.
• Isolated cleft palate is rarely diagnosed on prenatal
ultrasound and is often associated with micrognathia and a
variety of syndromes.
• Micrognathia is best assessed on sagittal midline views,
can be associated with a variety of syndromes, and may
lead to dificulties with feeding and airway management.
• Fetal neck masses are uncommon, and include lymphatic
malformations, teratomas, hemangiomas, and
thyromegaly. Evaluation of the fetal airway in relation to
the mass is critical for delivery planning.
CHAPTER OUTLINE
EMBRYOLOGY AND DEVELOPMENT
Face
Neck
SONOGRAPHY OF THE NORMAL
FETAL FACE
ABNORMALITIES OF THE HEAD
Abnormal Size
Abnormal Shape
Craniosynostosis
Wormian Bones
Forehead Abnormalities
Encephaloceles
ORBIT ABNORMALITIES
Hypotelorism
Hypertelorism
Microphthalmia and Anophthalmia
Coloboma
Dacryocystocele
Congenital Cataracts
EAR ABNORMALITIES
MIDFACE ABNORMALITIES
Hypoplasia
Absent Nasal Bone
Other Nasal Abnormalities
Cleft Lip and Palate
Unilateral Cleft Lip or Palate
Bilateral Cleft Lip or Palate
Median Cleft Lip or Palate
Unusual Facial (Tessier) Clefts
Isolated Cleft of Secondary Palate
LOWER FACE ABNORMALITIES
Macroglossia and Oral Masses
Micrognathia and Retrognathia
SOFT TISSUE TUMORS
NECK ABNORMALITIES
Nuchal Translucency and Thickening
Lymphatic Malformation (Cystic
Hygroma)
Cervical Teratoma
Thyromegaly and Goiter
CONCLUSION
Acknowledgments
With technical advances in gray-scale and three-dimensional
(3-D) imaging, sonographic evaluation of the fetal face
and neck has become a routine part of the second-trimester fetal
anatomic survey. 1 An increasing number of craniofacial anomalies
are detectable in the irst trimester. Abnormalities of the fetal
face are particularly important because they are frequently
associated with syndromes and chromosomal anomalies. his
chapter reviews the embryology and normal development of the
fetal face and neck and describes anomalies that can be detected
sonographically.
EMBRYOLOGY AND DEVELOPMENT
Face
Fetal face development begins at approximately 4 weeks’ gestation
and rapidly progresses, with the completion of major events by
8 weeks’ gestation (Fig. 33.1). In this complex process, ectoderm,
mesoderm, endoderm, and neural crest cells all interact to develop
the classic human facial features. Ectoderm surrounds the stomodeum
(primitive mouth). he paired pharyngeal arches, or
branchial arches, composed of central mesenchyme with outer
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