My Baby “startles” while asleep

Sleep startles in babies are common and healthy. Here’s what to know and how to help your little one rest easy

Inspired to write this after a mum of a three month old described her infant as jerking- and then proceeded to show me a video of what her baby’s movements looked like- The baby in the video was doing what we would describe as a “startle” also called a Moro reflex.

Sleep startles are normal and temporary. They are also a healthy sign of your baby’s developing nervous system.

Babies sometimes jerk or fling out their arms and legs when they are falling asleep or if they are startled- the trigger is usually a noise, movement or even the sensation of falling- which is how Paediatricians elicit the More reflex when examining newborns.

The Moro or startle reflex is a completely normal reflex which completely goes away by age 3-6 months. It is a primitive reflex that tells us that the baby’s nervous system is working well as of the time of checking. It is also more apparent when baby is overtired and in light sleep. While it might sometimes wake them up (frustrating, but not scary), it is nothing to worry about.

How can you help your baby?

When babies are under age two months, you can swaddle them. It basically mimics the cocooning of the womb and is safe to do until about 8 weeks of age. Thereafter it is not advised.

White noise - a quiet fan, a gentle buzzing noise in baby’s ears - and soft rocking movements may help reduce the frequent night wakenings- well- it keeps mum and dad up, but eventually everyone goes to sleep.

Holding baby close with his arms on your chest; also laying him down slowly and keeping your hand under him for a short Ime and then leaving your hand on his chest for a short time thereafter is also helpful.

While many people might not recommend pacifiers, we recommend them when babies are definitely above age two months and you can no longer swaddle them and the startles keeps making them up at night. Hopefully by this age, breastfeeding is well established and baby is able to indicate the need for breast milk on demand.

When should you take baby to hospital?

If the startles or the Moro reflex persists beyond age six months

If one side seems weak, and baby startles only on one side

Whenever you are worried about your baby’s sleep or movements.