Hydrocephalus in Newborns and Infants — Symptoms, Diagnosis and What Parents Face in the First Weeks
You may have been handed a word — hydrocephalus — and still feel completely in the dark. A scan has come back with results. A doctor has spoken carefully. And now you are sitting somewhere — maybe in a hospital corridor, maybe in your car — trying to hold the shape of a word you have never had to hold before.
This article is not going to rush you. Take what you need from it, and leave the rest for later.
What Hydrocephalus Actually Means for a Newborn
The brain and spinal cord are bathed in a fluid called cerebrospinal fluid — CSF. In a healthy brain, this fluid circulates freely, cushions the brain, delivers nutrients, and drains away at roughly the same rate it is produced. When something interrupts that balance — a blockage, a narrowing, or overproduction — fluid accumulates inside the ventricles (the fluid-filled spaces) of the brain. The pressure builds.
In adults and older children, the skull is fixed. In newborns and infants, the skull plates have not yet fully fused. This means the head will grow to accommodate the pressure — and this is actually why hydrocephalus in infants can sometimes be caught early, before crisis, if someone is looking.
Hydrocephalus can be congenital — present from birth — or acquired, meaning it develops after birth due to an infection, bleed, or injury.
The Signs to Watch For in a Newborn or Young Infant
These signs are different from how hydrocephalus presents in older children. If you are caring for a baby or know someone who is, these are the things that should prompt a paediatric assessment.
Rapidly growing head circumference. Doctors measure a baby’s head at every check-up for this reason. Head circumference growing faster than the expected curves on the chart, or noticeably larger than the baby’s chest circumference, warrants investigation. This is often the first sign.
A bulging or tense fontanelle. The fontanelle — the soft spot on top of a baby’s head — is normally soft and slightly sunken when the baby is calm and upright. When intracranial pressure rises, it can become firm or bulging, even at rest. Some bulging when crying is normal; persistent bulging is not.
Visible scalp veins. As pressure increases and the head grows, the scalp can stretch and veins become more prominent and visible. This can be alarming to see but is a recognised sign.
The sunsetting sign. This refers to the eyes appearing to look downward, with a visible band of white above the iris — as if the eyes are “setting.” It is caused by pressure on specific structures in the brainstem. In a young infant, this may present as a fixed downward gaze, difficulty looking upward, or eyes that appear different from how they looked before.
Irritability and high-pitched crying. Pressure-related headache in an infant manifests as inconsolable, unusual crying — often described as high-pitched or different from the baby’s normal cry. This combined with any other sign above should always be assessed urgently.
Poor feeding and vomiting. Raised intracranial pressure affects the brain’s feeding and vomiting centres. A baby who is consistently refusing feeds, vomiting forcefully (projectile vomiting), or failing to gain weight alongside other signs needs to be seen.
Unusual sleepiness or reduced responsiveness. A baby who seems increasingly difficult to rouse, or who is responding less than usual to faces and voices, is showing signs that need immediate attention.
How Hydrocephalus in Newborns Is Diagnosed
If a doctor suspects hydrocephalus, the investigation pathway typically includes:
Ultrasound through the fontanelle — a simple, radiation-free scan that can be done at the bedside and gives clear images of the ventricle size in young babies whose fontanelle is still open.
MRI scan — provides detailed images of the brain, the fluid spaces, and any structural causes such as blockages or narrowings. For newborns, this may require sedation or general anaesthesia.
CT scan — occasionally used in urgent situations. Less preferred for infants due to radiation, but faster when speed matters.
Diagnosis often comes alongside a search for the underlying cause — because hydrocephalus is a symptom of something, not a disease on its own. The cause shapes the treatment.
What the Research Shows
A 2021 meta-analysis by Sobana et al. published in Child’s Nervous System — reviewing neurodevelopmental outcomes in children who received VP shunt placement — found that outcomes are significantly influenced by the underlying cause of hydrocephalus and the timing of intervention. Earlier treatment is consistently associated with better neurodevelopmental results. Research published in Archives of Disease in Childhood Fetal and Neonatal Edition (de Vries et al., 2019) found that intervention thresholds and timing significantly affect outcomes in infants with posthemorrhagic ventricular dilation — reinforcing that clinical decisions about when to act matter greatly for this age group.
What This Means for Your Family
If hydrocephalus has just been identified in your newborn, you are likely somewhere between shock and a desperate search for information. Both of those responses make complete sense.
What is worth holding onto in these early days: newborn hydrocephalus is not a death sentence. Many babies diagnosed with hydrocephalus go on to lead full, active, meaningful lives. The brain in infancy has extraordinary plasticity — its ability to adapt and reorganise after insult is something researchers are still trying to fully understand.
The treatment — typically a VP shunt, or in some cases an ETV — is aimed at controlling the pressure and giving the brain the conditions it needs to develop. The shunt is not the end of the story. It is the beginning of management.
Ask your team directly: what is the cause of the hydrocephalus in our baby? That answer will shape everything that comes next.
Questions to Ask Your Paediatric Neurosurgical Team
- What is the likely cause of the hydrocephalus in our child?
- How urgently does treatment need to happen?
- Which treatment is recommended — VP shunt, ETV, or something else — and why?
- What is the expected outcome for our baby given their specific diagnosis?
- Will our baby need developmental follow-up — physiotherapy, speech therapy, or other support?
- What monitoring will happen after treatment, and for how long?
- Are there any support groups or families you can connect us with who have been through this?
You did not choose this. No parent does. But you found this page, which means you are already doing one of the most important things a parent can do: learning, so that you can advocate. Keep going. Your child needs exactly the parent you are becoming.
This article is written for informational purposes only and does not constitute medical advice. Always consult your neurologist, pediatrician, or qualified healthcare provider for diagnosis and treatment decisions specific to your situation. Read our full medical disclaimer at braincarepath.com/disclaimer/
- Sobana M, Halim D, Aviani JK, Gamayani U, Achmad TH. Neurodevelopmental outcomes after ventriculoperitoneal shunt placement in children with non-infectious hydrocephalus: a meta-analysis. Childs Nerv Syst. 2021;37(4):1055-1065. Available at: https://pubmed.ncbi.nlm.nih.gov/33479825/
- de Vries LS, Groenendaal F, Liem KD, et al. Treatment thresholds for intervention in posthaemorrhagic ventricular dilation: a randomised controlled trial. Arch Dis Child Fetal Neonatal Ed. 2019;104(1):F70-F75. Available at: https://pubmed.ncbi.nlm.nih.gov/29440132/
- Sanderfer VC, Arnold MR, Mulvaney GG, et al. Outcomes of laparoscopic and open ventriculoperitoneal shunt placement. Am J Surg. 2024;227:123-126. Available at: https://pubmed.ncbi.nlm.nih.gov/37827869/