Overview 

Plagiocephaly, or “flat head syndrome”, is an asymmetric shape of the baby’s head caused by flattening on one side. There are two main types of plagiocephaly, called “synostotic” (craniosynostosis), and deformational plagiocephaly.¹

 Craniosynostosis is a rare condition caused by the premature fusion of the baby’s cranium bones, affecting the growth and development of the brain, and causing complications, like developmental delay.² 

Deformational plagiocephaly has been very common in recent years due to the “Back to sleep” campaign, which advocated putting babies to sleep on their backs, to prevent sudden infant death syndrome. 

Although the campaign was successful, deformational plagiocephaly cases became more common. Deformational plagiocephaly results from external forces acting on the baby’s head, changing its shape.³ It is a “benign and minor cosmetic condition”, but recent studies suggest that it is a risk for developmental delays.^4,5

The link between deformational plagiocephaly and developmental delays is evident in the scientific literature; the cause-effect relationship is yet to be understood. This article focuses on the association between plagiocephaly and developmental delays, covering some general aspects of deformational plagiocephaly and developmental delays. Craniosynostosis and its association with developmental delay is beyond the scope of this article. 

What is plagiocephaly?

Plagiocephaly, deformational or positional, is asymmetry caused by external forces acting inside the womb, during birth, or in the early period after birth, deforming the baby’s head. It is a treatable paediatric condition, affecting around 22% of babies at 7 weeks. The rates improve by the age of 2, decreasing to around 3%.3 Baby’s head is asymmetric, and the skull is parallelogram shaped with flattening on one side of the back of the head. There can also be changes in the forehead of the baby, on the same side with the flattening.⁴

Causes of plagiocephaly

• Putting the baby to sleep in the same position in the first weeks of life-assisted birth Firstborn child 
• Lack of tummy time 
• Baby neck problems, such as congenital muscular torticollis

Males at birth have a higher risk because they have an accelerated growth rate head volume and less flexibility.^1,3 

A paediatrician can assess if your baby has plagiocephaly or not. The clinical examination will include:

• Measuring the baby’s head diameter to evaluate the severity of plagiocephaly
• Examining the neck muscles and movements to identify possible torticollis

Sometimes a computer tomographic scan with three-dimensional reconstruction (3D CT) may be needed if craniosynostosis is suspected.^1,3 

Positional plagiocephaly can be treated non-invasively with posture change while sleeping, adequate tummy time, physiotherapy, and cranial remoulding orthotics, called helmet therapy. Easy ways to prevent plagiocephaly are alternating the baby’s sleeping position on both sides and spending some tummy time for 10 to 15 minutes 3 times a day.¹ 

What is developmental delay? 

The growth and development of human beings is a complex process, beginning inside the womb and continuing into childhood, adolescence, and even partly into adulthood.⁶ Developmental delays happen when the baby reaches the expected developmental milestones later than other children of the same age. The areas of development include motor (movement), sensory, cognitive (thinking), speech and language, and social and emotional skills. 

Doctors monitor the baby during the well-baby care visits in the first year of life keeping track of the baby’s developmental milestones, the first smile, rolling over, sitting, standing, first steps and words, to assess developmental delays. 

The delay can be:

• Isolated if a single area of development is affected 
• Multiple when two or more regions are affected
• Global when the delay is significant in most regions of development⁶ 

The cause of developmental delay is unknown, and the prognosis is optimistic because the delays resolve spontaneously, and the babies finally catch up with their peers. However, in some cases, it is caused by genetic predisposition or conditions, environmental factors or events happening before, during, or after birth, causing developmental delay or even developmental disorders. These cases can be severe, with other complex health complications, and require early intervention and a team of specialists to manage the case and ensure that the baby will have the best outcome.⁶ 

Is plagiocephaly linked to developmental delay? 

Studies demonstrate an association between plagiocephaly and developmental delay. However, no evidence suggests developmental delay is due to plagiocephaly. Some state that external forces cause plagiocephaly causing developmental delay, while others state developmental delay is caused by plagiocephaly. Environmental positional limitations also cause plagiocephaly, and motor delay, leading to cognitive delay.^4,5,7,8,11

A large study demonstrated a significant association between positional plagiocephaly and developmental delay, stating plagiocephaly can be considered a risk for developmental delay. The 3-month-old were more likely to show developmental delays by 15 months compared to 24 months in those without Plagiocephaly. It suggests that Plagiocephaly could be a risk for developmental delays. .⁷

Motor and delays are associated with plagiocephaly. Motor delays are linked to plagiocephaly because there is a strong connection between neck problems, torticollis and positional plagiocephaly. Motor delay influences other areas of development, such as language, social interaction and early communication skills of the baby and affects, cognitive development and there is not yet enough evidence to support this..^3,5,7,10

According to The American Academy of Pediatrics, infants should be evaluated for plagiocephaly during routine well-baby care visits in the first year of life. Some preventive measures to stop the progression of plagiocephaly are parent counselling about adequate “tummy time”, posture change therapy, and stretching. If these do not yield results within 4 to 6 months, a Paediatric neurosurgeon or a specialist should be consulted. If the baby also has torticollis ( a condition causing neck muscle tightening) which does not improve with stretching, physiotherapy is indicated.⁷

The association between the severity of the plagiocephaly and the prediction of neurodevelopmental (the development of the reflexes and the brain) delay is controversial amongst different studies. The complexity of deformational plagiocephaly can’t predict developmental delay in the future in an infant, evaluating babies for developmental delays and early intervention is recommended.⁸ 

 The more severe the deformational plagiocephaly is, the more likely that the child will have neurodevelopmental delay. The more asymmetric and compressed the baby’s skull is, the more the brain will be affected and the child will have cognitive and motor delays. Head indexes are measured to predict the neurodevelopmental delay, and to recommend rehabilitation therapy at the right time.⁹

Summary 

Plagiocephaly is an umbrella term defining the asymmetry of the head, regardless of the causative factors, covering both entities – craniosynostosis and deformational plagiocephaly. Plagiocephaly is linked to developmental delay because craniosynostosis, a rare congenital paediatric condition, if left untreated, leads to developmental delays. 

Plagiocephaly is the most common form of deformational plagiocephaly – a treatable, paediatric condition affecting babies in the first months of life, in the majority of cases, caused by putting the baby to sleep in the same position. The association between plagiocephaly and developmental delay is yet to be clarified. 

The association between deformational plagiocephaly and developmental delay is evident in several studies, but these theories are debatable.. Studies have acknowledged their limitations, but more research is required to prove a direct relationship.s. 

Deformational plagiocephaly, previously considered a “benign and minor cosmetic condition”, requires increased awareness regarding this possible link to developmental delays. Parents need to be aware and informed, and doctors trained on preventive measures and early interventions to be able to properly manage plagiocephaly and to ensure the best possible functional and cosmetic outcome for an affected child.