From the Guidelines
The workup for non-immune hydrops fetalis (NIHF) should begin with a comprehensive maternal and fetal evaluation, including an antibody screen, targeted sonography with echocardiography, MCA Doppler evaluation for anemia, and fetal karyotype or chromosomal microarray analysis, as recommended by the Society for Maternal-Fetal Medicine 1. The initial evaluation should include a detailed maternal history, physical examination, and laboratory testing, such as complete blood count, blood type, and TORCH infections screening, to identify potential underlying causes of NIHF.
- Fetal assessment should include:
- Detailed ultrasound to evaluate for structural anomalies
- Fetal echocardiography to assess cardiac structure and function
- Middle cerebral artery Doppler to evaluate for fetal anemia
- Additional testing may include:
- Amniocentesis for karyotyping, chromosomal microarray analysis, and specific genetic testing
- Cell-free DNA testing for rapid aneuploidy screening
- Fetal MRI if CNS abnormalities are suspected
- Cordocentesis for direct fetal blood sampling to evaluate for anemia, infection, or metabolic disorders This comprehensive approach is necessary because NIHF has numerous potential causes, including cardiovascular, chromosomal, genetic syndromes, hematologic, infectious, and structural abnormalities, and identifying the specific etiology is crucial for appropriate management and counseling regarding prognosis, as highlighted in the Society for Maternal-Fetal Medicine clinical guideline 1.
From the Research
Workup for Non-Immune Hydrops Fetalis
The workup for non-immune hydrops fetalis (NIHF) involves a comprehensive evaluation to determine the underlying cause of the condition. Some key steps in the workup include:
- Prenatal ultrasonography to detect abnormal accumulation of fluid in two or more fetal compartments 2
- Genetic testing, including chromosomal analysis and evaluation for lysosomal storage disorders (LSD) 3, 4
- Ultrasound scans to detect anatomical abnormalities, such as cardiac malformations and renal abnormalities 3
- Evaluation for congenital infections and metabolic causes, including inborn errors of metabolism (IEM) 5, 4
- Autopsy of all fetuses or neonates who die from NIHF to determine the underlying cause of death 6
Diagnostic Challenges
Diagnosing the underlying cause of NIHF can be challenging, and in some cases, the diagnosis may not be established throughout pregnancy 3. A diagnostic flow-chart for NIHF has been suggested to help guide the evaluation process 5. The workup should be individualized for each case, and a multidisciplinary approach may be necessary to determine the underlying cause and develop an appropriate treatment plan.
Importance of Early Detection
Early detection of NIHF is crucial, as it allows for prompt evaluation and treatment of the underlying cause 6. The prognosis for NIHF is generally poor, with a high mortality rate, especially in cases with severe hydrops, prematurity, and chromosomal disorders 6, 4. However, in some cases, spontaneous resolution of the hydrops may occur during pregnancy 4.