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January 8, 2018

While relatively rare, birthmarks are something many parents find themselves dealing with after the birth of their baby, explains Paulette Crowley...

Since the records of time, birthmarks have been a source of mystery and cultural superstition. The ancient Greeks even believed these special marks foretold the bearers destiny. These days, a baby with an obvious birthmark usually just invokes concern for a parent and raises questions. Is it harmful? Is it permanent? Will they be teased at school? Will they forever have to explain their different appearance? 

Thankfully, due to medical advancement, birthmarks are no longer an enigma or a life sentence.  While many, of the cosmetic variety, will disapear on their own, for the others, effective treatment options have come in leaps and bounds - even in the last 10 years. This includes a medication which has shown an almost immediate reduction of those birthmarks connected to serious complications such as blindness or epilepsy. 

Ask the Doctor...

Doctor Swee Tan has seen many Kiwi babies, children and adults at the Centre for the Study and Treatment of Vascular Birthmarks, which he founded at Hutt Hospital in 1996. Dr Tan spoke to Little Treasures Magazine about the different types of vascular birthmarks that can affect our kids, and what can be done about them. 

What are the main types of vascular birthmarks?

There are many types, tumours and malformations, affecting up to 12 per cent of the population and they all need different treatment. They’re present at birth, grow proportionately with the child and can suddenly expand in response to hormonal changes or trauma. The most common type of vascular tumours are strawberry birthmarks, also known as infantile haemangiomas. The most common form of vascular malformations are venous malformations that affect veins in a particular part of the body. Port wine stains are a vascular malformation that affect capillaries, usually of the skin, so they are visible.

Why do they happen at birth?

The word ‘birthmark’ is actually not quite an accurate term for strawberry birthmarks because 40 per cent are not present at birth. They’re usually noticed during the first 2-3 weeks of life as a pink patch or dilated capillary vessels if they affect the skin. However, some aren’t noticeable until 2-3 months of age if they affect the tissue underneath the skin. Our research has shown that strawberry birthmarks are caused by stem cells from the placenta that travel to the baby in utero. 

Where do strawberry birthmarks usually appear? 

Strawberry birthmarks affect up to 10 per cent of newborns in New Zealand. About 60 per cent of them affect the face and neck area and they range from really tiny to something very big – some can even cover half the face. But most are generally small and don’t cause any trouble, except for cosmetic effect.

Do they go away?

Mostly. They can grow for 9-10 months, although they are all different. Usually, they will gradually shrink on their own spontaneously, although that can take five, sometimes 10 years. About 10-15 percent of strawberry birthmarks need intervention in the first year of life. Overall, about a quarter of them will require some sort of intervention, even when they have shrunk.

Which type of strawberry birthmarks require medical intervention during infancy?

If they cause a threat to function, for example, if the birthmark is around the mouth, the baby might not be able to feed properly; if it’s on the nose or windpipe it might affect breathing; near the eye, the baby may go blind. About five per cent of strawberry birthmarks can become ulcerated and cause pain and bleeding and can become infected. This causes distress to the baby and parents. Occasionally when these strawberry birthmarks are very large, especially those that affect the liver, a lot of blood flows in and out of it and in fact it can cause heart failure.

What is the treatment for strawberry birthmarks?

We can manipulate these birthmarks with specific medication to cause them to ‘commit suicide’. The medication is propranolol, which is usually used to treat blood pressure. It works very dramatically on strawberry birthmarks, with most responding really well and shrinking within a few days. 

What about venous malformations?

Venous malformations are the most common type of vascular malformations, affecting one per cent of the population (one per cent of these run in the family). Those situated underneath the skin look bluish in colour and can get confused with strawberry birthmarks that affect the tissue underneath the skin. 

What is the treatment for venous malformations?

Venous malformation may cause functional problems such as pain and loss of function and cosmetic concerns because of the distortion of the affected part of the body. The treatment is usually postponed until the child is older and it involves surgery or alcohol injections, and sometimes both.

What about port wine stains?

Port wine stains are caused by malformation in the capillaries. The dilated capillary vessels in the affected skin fill with blood, which causes the colour of the stains, which can be pink, red or purple. They can affect any part of the body but the face is most common. They affect about 0.3 per cent of the population. Although they’re not common, they can cause significant cosmetic concerns for the child and the parents. 

Port wine stains can look striking, but are they harmless?

Port wine stains are largely a cosmetic problem. Those that affect the face can be associated with a condition called Sturge-Weber Syndrome, which can cause neurological problems such as seizures and also glaucoma. Untreated port wine stains gradually darken and the skin may become thickened and there is sometimes overgrowth of the soft tissue and even the bone of the face. 

What is the treatment for port wine stains?

Pulsed dye laser treatment is the standard treatment, with an average of 8-10 sessions. They are painful and usually need to be performed under a general anaesthetic in children. Port wine stains can be removed completely in about one out of three patients and you can get improvement in the rest.

What is your advice to parents?

See your GP to get the right information and advice early. There are many different types of vascular birthmarks and they require different forms of treatment. For many, the right management is to do nothing and watch.

Facing Facts


  • Are the most common type of
  • vascular tumours. 
  • Affect up to one in 10 newborn babies
  • in New Zealand. 
  • Are benign tumours, known also as
  • infantile haemangiomas.
  • Are caused by lots of closely packed immature tiny blood vessels, which may affect any part of the body, most commonly the skin (which then looks crimson in colour) and/or tissue under the skin (which then looks bluish in colour). 
  • Are mostly small and regress on their own over five to 10 years. About one in four will eventually need some form of intervention, usually surgery or laser therapy.
  • Require intervention during infancy in 10-15 per cent of cases because they interfere with function (e.g. vision or breathing) or become ulcerated.


  • Are the most common type of
  • vascular malformations.
  • Affect one per cent of the population. 
  • Most commonly affect the skin and the tissue underneath the skin, but can affect any tissues in the body. 
  • Are usually bluish in colour and are often confused with strawberry birthmarks that are situated underneath the skin.
  • Get bigger over time, rather than regressing as seen in strawberry birthmarks.


  • Affect 0.3 per cent of the population. 
  • Are a type of vascular malformation that typically affect capillaries in the skin, but sometimes deep tissues also.
  • Cause cosmetic concerns but can be part of Sturge-Weber syndrome, which causes epilepsy and/or glaucoma. 

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