with thanks to Dr Harriet Clompus.

Assessment of fontanelles is an important part of the six week check.  Large fontanelles may indicate a problem in bone ossification or hydrocephaly, while a fused anterior fontanelle can indicate craniosynostosis.  These need to be referred to paediatric outpatients.  Always remember that anterior fontanelle size is very variable (1-4.7 cm in any direction) and always needs to be assessed in context of baby’s head circumference.

A sunken fontanelle indicates dehydration, while a bulging fontanelle indicates raised intracranial pressure (but can be non-pathological – vomiting, crying, coughing – so assess when baby settled!).  These can be discussed with paediatric registrar on-call.

1)      The anterior fontanelle is diamond shaped, 1-4.7 cm in any direction at birth (black infants larger than white) and can widen in first 2 months of life.  Median age of closure is 14 months (4 – 24 months)

 2)      The posterior fontanelle is triangular and is less than 1 cm.  It closes by 6 – 12 weeks.


 3)      The size of the fontanelles should always be assessed in conjunction with the head circumference. 

  • Macrocephaly  – familial, hydrocephaly or skeletal disorders such as achondroplasia.
  • Microcephaly  – familial, congenital infections, fetal alcohol syndrome, trisomies

 4)      The quality of the fontanelle  should always be assessed. 

  • Soft fontanelle  – normal
  • Bulging fontanelle – raised intracranial pressure (hydrocephalus, meningitis/encephalitis) .  NB can be non-pathological in crying, coughing or vomiting infant.
  • Sunken fontanelle – dehydration


 1)      WIDENED FONTANELLES:  think of…






Congenital  Rubella

Neonatal Hypothyroidism (3rd fontanelle)

Osteogenesis Imperfecta



 Rickets – Think of rickets in darker skinned, breast fed babies, especially if mothers are veiled.  Infants will often have sweating on the head.  If widened sutures are found check neonatal blood spot for hypothyroidism and refer to outpatients.

 Hydrocephalus – can have widened, bulging fontanelles in conjunction with a large head.


Closure of anterior fontanelle by six weeks always pathological  (NB  by 3 months 1% of normal infants will have a closed anterior fontanelle). 

Must always assess in conjunction with head circumference – early fusion associated with microcephaly (and less commonly, macrocephaly).

Craniosyntosis is premature closure of cranial suture(s) with skull growth restriction perpendicular to fused suture and compensatory skull overgrowth in unrestricted areas.   Presents with ridging (always pathological beyond one week of life) and abnormal skull shape (usually later than six weeks).

There is a nice background overview (with useful diagrams) to craniosynostosis at

Primary craniosynostosis is due to abnormal ossification of one or more sutures.  Simple – premature fusion of one suture, complex – premature fusion of multiple sutures.  Causes include rickets, hyperparathyroidism, hyperthyroidism , idiopathic and genetic causes such as Aperts.

Secondary craniosynostosis is caused by premature closure of ALL sutures due to lack of primary brain growth. If you find a child with premature closure of fontanelles or over-riding sutures at six week check you should refer to paediatric outpatients. NB Plagiocephaly (flat occiput) is a non-pathological deformation due to ‘back to sleep’ position – no action required.  It presents with ear on flattened side presenting anteriorly.  Parallelogram shaped head (as opposed to lambdoid suture craniosynostosis trapezoid shaped)

The following articles give lots of information on fontanelles and/or sutures.  The Fuloria article is very thorough and although it focuses on neonatal examination, most of it is still relevant for the six week check.

1) The Abnormal Fontanel, J KIESLER et al Am Fam Physician. 2003 Jun 15;67(12):2547-2552.  (figure 2 taken from abnormal fontanel)

2)The Newborn Examination: Part I. Emergencies and Common Abnormalities Involving the Skin, Head, Neck, Chest, and Respiratory and Cardiovascular Systems, Fuloria et al, Am Fam Physician. 2002 Jan 1;65(1):61-69.



5) Craniosynostosis, P Raj et al, emedicine jul 2010 Craniosynostosis : eMedicine Neurology


  1. On the subject of positional plagiocephaly, patients may ask about helmets to re-mould their child’s head. This is still a controversial area with little evidence behind the wearing of a helmet for many hours a day for many weeks. They are not available on the NHS as far as I am aware. I have heard on the grapevine that there is some new work coming out at the moment on their efficacy but, for the moment, I think I would agree with the sentiments expressed in Great Ormond Street’s patient/parent information sheet available at However, if parents really want to look into the use of LOCbands (helmets) for plagiocephaly, there is a private clinic in London they can have a free initial assessment at, see

  2. Continuing on the subject of plagiocephaly;

    Plagiocephaly (an asymmetric head shape) has multiple causes. Prevalence: 5% to 48% in healthy newborns. Different from the cranial moulding associated with childbirth, which usually resolves spontaneously in the first weeks of life. Worldwide increase of positional plagiocephaly has been linked to the various “Back to Sleep” campaigns.

    Management of positional plagiocephaly is advise: Positioning. Eg spend more time on abdomen when awake, rolled-up towel placed behind the child’s back will help to exert less pressure on the flattest part of the head

    Ref: Saeed et al, Arch Dis Child 2008;93:82-84 doi:10.1136/adc.2006.093740

    1. This is what I wrote in July on my other website that has more patient/parent centred information on it: The London orthotics clinic is private but provide an initial free consultation if that would interest your patient’s parents ( The most up to date look at the evidence I can find is from 2008 ( One of my colleagues here has a bit of an interest in plagiocephaly. I will ask him if there is any relevant recent research.


      1. Full content 2011 paper on prognosis in plagiocephaly:

        It seems they get better anyway. Helmets are not mentioned in this paper. My colleague says that some neurosurgeons use them in children with craniosynostosis but that they are probably not required for simple positional plagiocephaly.


    2. Since the advent of the “Back to Sleep” campaign, launched by Anne Diamond, there has been a vast increase in numbers of patients with posterior plagiocephaly.
      The problem arises early, once a preference for lying on one side is demonstrated. Then, there’s a flattened area and the preference becomes more pronounced and this further enhances the flattening and the cycle continues.

      Positional Plagiocephaly will remodel spontaneously if the baby is positioned differently – as already indicated below. I cannot give a percentage figure as none currently exists. But, taking care over re-positioning the child certainly does work.
      Also of note, despite running our craniofacial clinic in Leeds for 15 years, we have not had older children referred with ongoing positional plagiocephaly. I know this doesn’t prove that it is self-correcting but its an interesting observation.

      As far as moulding helmets are concerned, there is no randomised control trial evidence to prove efficacy.
      They are available from a variety of sources privately, many of whom do a number of measurements and scans to demonstrate a before and after.
      There is an argument that going for a helmet will help adjust for a sleeping preference and allow the natural remodelling to occur but their efficacy is not proven.

      So, in short, our normal advice is that positional plagiocephaly will self-correct if care is taken over positioning the baby, and we do not recommend helmets.

      Hope this helps


      Mr John Goodden
      Paediatric Neurosurgeon, Leeds, UK

  3. Just thought you would like to know that helmet treatement is available on the NHS at Frenchay hospital (see post below):

    From: KA

    Date: 10 January 2011 17:40:55 GMT

    Subject: Treatment for plagiocephaly

    Dear Ms O,

    Thank you very much for your email. N passed your message on to me as I am one of the paediatric consultants in the department.

    I can confirm that we do see children with plagiocephaly on the NHS and we offer them free NHS treatment. The hospital tariff cost for the helmet, which includes a brief anaesthetic to mould the helmet, is £660.

    Hope this helps. Please let me know if I there is anything else I can do.

    Yours sincerely,


    Consultant paediatric neurosurgeon

    Department of Neurosurgery

    Frenchay Hospital


    North Bristol NHS Trust –

    Here is some further info for you on accessing the treatment (see below):

    FOI 1011 367

    Summary Issue – Plagiocephaly


    I am aware that Bristol PCT is providing treatment for children with

    Plagiocephaly. I know that the helmets are provided by Frenchay

    Hospital. As I am sure you are aware most PCT’s in the UK do not

    provide treatment on the NHS for plagiocephaly. I am wondering if you

    could advise why Bristol have decided the treatment should be offered

    to babies in your area?


    This is not a Bristol only service

    It is a regional service commissioned by the South West

    Specialised Commissioning Group for the South West

    and provided by North Bristol NHS Trust at Frenchay

    Hospital. The cost of the helmet is included in the total

    procedure cost and there is no additional cost to the


    The moulding cap treatment at Frenchay was set up

    originally for post-operative treatment for babies having

    cranial remodelling procedures for delayed diagnosis –

    synostosis, but has been used for many years to treat

    babies with severe plagiocephaly that has not

    responded to standard postural measures. North Bristol

    NHS Trust believe sufficient evidence exists to support

    the technique in reducing the risk of long term cranial

    deformity and avoiding a few of them having big

    craniofacial remodelling operations

    The information provided in this response is accurate as of 28 March 2011

    Complaints & FOI Manager
    NHS Bristol

    I would also ask you to consider the other posibilities of Craniosynostosis (such as Lambdoid Suture) where the head measures greater than 12mm particularly if the Mother is:

    Older Mother
    Taking SSRI (Fluoxetine)

    As all of the above greatly increase the risk of some form of Craniosynostosis and Fluoxetine has been identified in causing other birth defects such as heart and lung problems in babies….

  4. Dear Mr. Goodden,

    My daughter is 4 months old and at 1 month i notticed that she has a flat head behind. I started to use a correction pillow right away and kept her in my arms most of the time. At 2 months she started sleeping on her belly and we continued to keep her as much as possible in our arms not to touch the head.When i saw no improvement from 3 months we started to make her sleep during the day on her back with the head on the left or right. Until then she was crying when we wanted to keep her like this. Even like this i see no big improvement. The head is still flat and the pediatrician told us that her anterior fontanelle is almost closed at the 4th month control. She said that everything looks in order neurologically. Her HC is 40.3 cm at 4 months. It is growing but not too fast..i thought the head is not too big because it is flat but now i think its because of the fontanelle.
    I wanted to use a helmet but now i’am affraid for her hed development. Can the helmet make it worse for the fontanelle and her head development? Is it any risk involved using the helmet when the fontanelle is almost clised?
    Thank you for an advice,

    1. Dear Corina

      Whilst you are welcome to read everything that is written here, Paediatric Pearls is an educational site aimed primarily at doctors. Unfortunately we can not answer individual questions about specific patients. Please see your own GP or health visitor if you have concerns about your daughter. I am sorry not to be able to help.

      Julia Thomson

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