From the Guidelines
Scalloping of the skull in a fetus is a concerning finding that requires immediate attention and further evaluation by maternal-fetal medicine specialists and pediatric neurosurgeons, as it can be associated with increased intracranial pressure and underlying conditions such as hydrocephalus, intracranial masses, or genetic syndromes 1.
Causes and Associations
The most common cause of scalloping of the skull in a fetus is hydrocephalus, where cerebrospinal fluid accumulates and exerts pressure on the developing skull bones. Other causes include intracranial masses, certain genetic syndromes, or craniosynostosis (premature fusion of skull bones) 1. Additionally, congenital Zika syndrome (CZS) has been described as a recognizable pattern of congenital anomalies associated with ZIKV infection during pregnancy, which can include severe microcephaly with a partially collapsed skull 1.
Management and Recommendations
When identified during prenatal ultrasound or MRI, this finding warrants further evaluation and a multidisciplinary approach involving neonatologists, neurosurgeons, and geneticists is typically recommended for optimal outcomes 1. The management depends on the underlying cause and may include close monitoring, in-utero interventions in severe cases, or planning for postnatal treatment. Parents should be counseled about the potential implications, and the significance of skull scalloping varies based on other associated findings, gestational age, and the progression of the condition.
Key Considerations
It is essential to consider the potential long-term child outcomes and the need for a broadened public health approach to address the needs of children affected by congenital Zika syndrome and other conditions associated with skull scalloping 1. The lifetime medical and educational costs, as well as the emotional impact for children and families affected by these conditions, are likely to be substantial, and a sustained approach with dedicated resources is necessary to support affected children and help them reach their full potential 1.
From the Research
Fetal Skull Abnormalities
- Scalloping of the skull in a fetus can be an indicator of various congenital anomalies, including craniospinal anomalies and neural tube defects 2, 3.
- The diagnosis of fetal skull abnormalities can be challenging, and prenatal ultrasonography may not always provide accurate results 4, 5.
- Magnetic Resonance Imaging (MRI) can be used to further evaluate suspected fetal skull abnormalities and provide more accurate diagnoses 2, 4, 3.
Detection of Craniospinal Anomalies
- A study found that MRI diagnosis was completely correct in 75.9% of cases, while US diagnosis was correct in 58.6% of cases 3.
- The diagnostic performance of MRI was significantly higher than that of US, and MRI contributed to US by either changing the wrong US diagnosis, demonstrating additional findings, or confirming suspicious US diagnosis in 28.7% of cases 3.
- Fetal MRI can facilitate the evaluation of the palate, micrognathia, cranial sutures, brain, and other fetal structures, especially in cases of craniofacial abnormalities 5.
Importance of Accurate Diagnosis
- Accurate diagnosis of fetal skull abnormalities is crucial for proper counseling, planning of deliveries, and potential fetal interventions 2.
- A systematic approach to the fetal skull and face can increase the detection rate of craniofacial abnormalities, and the use of 3-/4-dimensional ultrasound may be useful in the assessment of cleft palate and craniosynostosis 5.
- Invasive prenatal diagnostic techniques may be indicated to exclude chromosomal abnormalities, and molecular analysis for some syndromes is feasible if the family history is suggestive 5.