From the Guidelines
When a fetal cystic hygroma is detected during pregnancy, a comprehensive workup is recommended, starting with a detailed ultrasound to assess the size and location of the hygroma, and a fetal echocardiogram to evaluate for cardiac defects, as outlined in the most recent guidelines 1. This approach is crucial because cystic hygromas are often associated with chromosomal abnormalities, such as Turner syndrome (45,X) and Down syndrome (trisomy 21), which can significantly impact the prognosis and management of the pregnancy 1. Key components of the workup include:
- A detailed ultrasound to assess the size and location of the hygroma and to look for other structural abnormalities
- A fetal echocardiogram to evaluate for cardiac defects, which are commonly associated with cystic hygromas
- Genetic testing, including amniocentesis or chorionic villus sampling, to check for chromosomal abnormalities
- Cell-free DNA testing, which may be offered but is not a substitute for diagnostic testing in this situation
- Maternal serum screening for aneuploidy markers to provide additional information
- Regular follow-up ultrasounds, scheduled every 2-4 weeks, to monitor the hygroma's progression Consultation with a maternal-fetal medicine specialist, geneticist, and pediatric surgeon is important for comprehensive counseling about prognosis and management options, as the prognosis varies widely depending on associated abnormalities, with isolated hygromas having a better outlook than those associated with genetic syndromes or structural defects 1. The most recent and highest quality study 1 supports this comprehensive approach, emphasizing the importance of early detection and management of associated abnormalities to improve outcomes.
From the Research
Workup for Fetal Cystic Hygroma
The workup for a pregnant patient with fetal cystic hygroma involves several steps, including:
- Ultrasound diagnosis: Fetal cystic hygroma can be diagnosed using ultrasonography from the end of the first trimester of pregnancy 2.
- Cytogenetic analysis: A cytogenetic analysis should be performed on amniocentesis or fetal tissues to check for chromosomal abnormalities 2, 3, 4, 5.
- Detailed sonography: A detailed sonographic examination should be performed to check for associated anomalies 3, 4, 5.
- Genetic counseling: Genetic counseling is important for families of fetuses with cystic hygroma, especially if chromosomal abnormalities are found 2, 3, 5.
Associated Anomalies
Fetal cystic hygroma is often associated with other anomalies, including:
- Lymphedema 2
- Hydrops 2, 5
- Diminution of amniotic fluid 2
- Other abnormalities 2, 3, 4, 5
- Chromosomal abnormalities, such as Turner's syndrome, Edwards' syndrome, and trisomy 21 2, 3, 4, 5, 6
Prognosis
The prognosis for fetuses with cystic hygroma depends on several factors, including:
- Chromosome analysis: The presence of chromosomal abnormalities can affect the prognosis 2, 3, 4, 5, 6.
- Other ultrasound abnormalities: The presence of other anomalies can affect the prognosis 2, 3, 4, 5.
- Size of the cystic hygroma: The size of the cystic hygroma can affect the prognosis 2.
- Maternal age: Advanced maternal age can increase the risk of chromosomal abnormalities and adverse pregnancy outcomes 6.