Newborn reflexes and what they mean

The odd, jerky, automatic movements newborns make are not random — they are a defined set of reflexes that clinicians test because their presence, symmetry and timely disappearance say something about the nervous system.

The main ones

Moro, or startle: in response to a sudden change in position or a loud noise, the arms fling out, the fingers extend, and then the arms draw back in.

Present from birth and typically fading by around four to six months.

An asymmetric Moro can indicate a problem with a collarbone or nerve on one side.

Rooting: stroking the cheek causes the baby to turn towards it with an open mouth, which is what allows feeding to be found.

Sucking: present from before birth, and coordinated sucking, swallowing and breathing develops around thirty-four weeks of gestation, which is why very preterm babies need tube feeding.

Grasp: pressure on the palm produces a strong grip, fading by around five to six months, with a similar reflex in the toes lasting longer.

Stepping: held upright with feet touching a surface, a newborn makes stepping movements.

It disappears within a couple of months and is unrelated to later walking.

Tonic neck, or fencing: when the head turns to one side, the arm on that side extends and the other flexes.

Plantar, or Babinski: stroking the sole causes the toes to fan upward, which in adults would be abnormal and in infants is expected until around a year or two.

Why they are checked

Because they are one of the few windows into an infant nervous system.

Absence of an expected reflex, marked asymmetry, or persistence well beyond the expected age can indicate a neurological problem and prompts assessment.

Asymmetry is the feature that most reliably indicates a localised problem, such as a birth injury to a nerve or a fractured clavicle.

Their disappearance is also informative: primitive reflexes are suppressed as the higher brain develops, so persistence beyond the usual window can signal delayed development.

The claims to be sceptical about

An area with a commercial fringe.

Programmes marketed for retained primitive reflexes, offering exercises claimed to treat attention difficulties, learning problems and coordination disorders, have limited evidence.

Reviews of reflex integration therapies generally find weak or inconsistent support.

Which does not mean genuine persistence of reflexes is unimportant — it means the elaborate diagnostic and treatment industry built on it outruns what is established.

Genuine concerns about movement and coordination should go to a paediatrician or physiotherapist.

The other newborn behaviours

Not reflexes, and equally alarming to new parents.

Periodic breathing: irregular breathing with pauses of a few seconds followed by faster breaths, which is normal in newborns.

Pauses longer than around twenty seconds, or with colour change or floppiness, are not and need urgent assessment.

Sneezing and hiccups, both frequent and harmless.

Chin and limb trembling, which is normal neurological immaturity.

Noisy digestion and straining while passing stool, which in a baby passing soft stool is normal coordination practice rather than constipation.

Startling in sleep.

And crossed or wandering eyes in the early weeks.

What is not normal

Worth distinguishing.

Rhythmic, repetitive jerking that cannot be stopped by holding the limb, which may be a seizure and requires urgent assessment — normal jitteriness stops when the limb is held.

Persistent floppiness, or persistent stiffness.

Marked asymmetry of movement.

Not moving one arm at all, which may indicate a birth injury.

Absent or very weak sucking.

A high-pitched, continuous cry.

And any change from previously normal behaviour.

Neonatal seizures

Which look different from seizures in older children.

They may be subtle: repetitive lip smacking, cycling movements of the legs, eye deviation, or apnoea, rather than dramatic convulsions.

Any suspicion of a seizure in a newborn requires urgent medical assessment, since the causes are treatable and important.

What parents can usefully do

Observe and describe rather than diagnose.

Film anything unusual, which is enormously more useful to a clinician than a description and which is easy to do.

Note the timing, duration and what stopped it.

Attend the newborn and six-to-eight-week examinations, which are where these are checked systematically.

And raise anything asymmetric, since it is the single feature most likely to indicate something requiring attention and the one parents most commonly notice first.

General information only, not medical advice. Seek urgent assessment for suspected seizures, breathing pauses with colour change, floppiness, or an arm that is not moving.