Abstract
The fetal thymus is a lymphoepithelial structure that grows throughout fetal life and is located in the anterior mediastinum. It is apparent on ultrasound as a homogeneous, quadrangular structure anterior to the major vessels on the three-vessel and three-vessel-trachea view. The thymus can be measured easily in these transverse planes. The finding of thymic hypoplasia or thymic aplasia is clinically important and has been associated with genetic conditions, most commonly 22q11.2 deletion. Thymic hypoplasia is also associated with acquired conditions such as fetal growth restriction and fetal inflammatory response syndrome. A small thymus in fetuses with growth restriction, preterm labor, or preterm premature rupture of membranes may indicate a worse fetal prognosis.
Original language | English (US) |
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Title of host publication | Obstetric Imaging |
Subtitle of host publication | Fetal Diagnosis and Care, 2nd Edition |
Publisher | Elsevier |
Pages | 25-28.e1 |
ISBN (Electronic) | 9780323445481 |
DOIs | |
State | Published - Jan 1 2017 |
Keywords
- 22q11.2 deletion
- DiGeorge syndrome
- Fetal thymus
- Thymic aplasia
- Thymic hypoplasia
ASJC Scopus subject areas
- General Medicine