How Long Does the Newborn Scrunch Last? | Baby Reflex

The newborn scrunch typically lasts one to two months, fading as the baby’s nervous system matures and muscle control develops.

You bring your baby home and notice they curl up tight — legs tucked toward the belly, fists clenched, sometimes with a pouty face. It’s called the newborn scrunch, and it can look like your baby is trying to stay in the fetal position even outside the womb.

The scrunch is a normal reflex, not a sign of discomfort. Most babies outgrow it within the first couple of months as their nervous system matures and they start stretching out. Here’s what that timeline looks like and when it might be worth asking your pediatrician.

What Is the Newborn Scrunch?

The newborn scrunch isn’t one single reflex — it’s a combination of several newborn reflexes working together. Your baby curls up because their body is still wired to mimic the warm, snug position of the womb.

Pediatrician Dr. Nicola Chin explains that the scrunch is believed to involve the Moro reflex (the startle reflex) and the tonic neck reflex, which together cause babies to pull their limbs inward. It’s a normal part of early motor development.

Most of these reflexes begin fading around 6 weeks of age. By 1 to 2 months, many babies start elongating their arms and legs and spreading out during sleep and awake time.

Why Does the Scrunch Happen?

If you’re a new parent, seeing your baby scrunch can feel confusing — especially if they seem tense. But the scrunch is simply your baby’s immature nervous system responding to stimuli the way it’s used to. It isn’t necessarily a sign of being cold or uncomfortable.

• The Moro (startle) reflex: When a baby hears a loud noise or feels a sudden drop, they throw their arms out and then pull them back in. This reflex gradually disappears between 4 and 6 months, but the scrunch-like pulling-in is most noticeable in the first weeks.
• The tonic neck reflex: When the baby’s head is turned to one side, the arm on that side extends and the opposite arm bends. This reflex can take longer than 2 months to fully fade.
• The stepping reflex: Holding a baby upright with feet touching a surface makes them appear to take steps. This reflex usually disappears by about 2 months.
• The grasp reflex: Stroking a baby’s palm causes them to close their fingers. This reflex lasts until about 5 to 6 months of age, according to the Children’s Hospital of Philadelphia.

These reflexes are all normal. The scrunch is strongest when multiple reflexes happen at once, creating the curled-up posture you see.

When Should the Scrunch Fade?

Most babies show the scrunch regularly during the first month. Around 6 to 8 weeks, the scrunch typically becomes less noticeable as reflexes integrate and muscle strength builds. By two months, many babies start stretching their limbs out more often.

Parenting resource What to Expect notes that the newborn scrunch generally ends or becomes much less obvious after two months — see their scrunch ends after two months guide for more detail. Some babies hold onto the scrunch a bit longer, but by three months most are elongating during both sleep and wake periods.

Every baby develops at their own pace, so these timelines are typical ranges. If your baby seems to be scrunching well past two months, watch for other milestones — not just the posture.

What If the Scrunch Continues Beyond Two Months?

If your baby is still regularly scrunching at three or four months, it’s usually not a concern — some babies simply take longer to lose their reflexes. But there are guidelines for when to check in with your pediatrician.

1. Scrunching after six months. If the newborn scrunch posture is still present at six months, it’s worth mentioning to your doctor. Persistent reflexes beyond that age can sometimes signal delayed motor development.
2. Jitters that don’t stop. Some trembling in the arms and legs during crying is normal in newborns. If your baby is jittery when not crying, or if the jittering continues past 1 to 2 months, bring it up at a checkup.
3. Absence of other reflexes. If the scrunch is weak or missing in the first weeks, and your baby also seems very floppy or stiff, a pediatrician can evaluate overall muscle tone.
4. Concern about infantile spasms. Very rarely, a baby’s jerking movements are due to infantile spasms rather than normal reflexes. Distinguishing signs include clusters of repeated jerks that happen in series — a pediatrician can help differentiate.

In most cases, the scrunch fades naturally. Trust your instincts: if something feels off, a quick call to your provider can put your mind at ease.

Helping Your Baby Stretch and Grow

You don’t need to do anything special to make the scrunch go away — it will resolve on its own as your baby’s nervous system matures. But you can support development with safe positioning and gentle movement.

The Children’s Hospital of Philadelphia notes that the grasp reflex lasts 5-6 months, which means your baby will hold your finger tightly for weeks. That’s normal and part of the same reflex family as the scrunch. Offering supervised tummy time and allowing free leg movement (rather than tight swaddling) helps your baby practice extending their limbs.

These activities don’t speed up reflex fading, but they build the muscle control your baby needs to eventually leave the scrunch behind.

The Bottom Line

The newborn scrunch is a short-lived reflex combination that most babies outgrow within one to two months. It’s a normal sign of your baby’s nervous system adjusting to life outside the womb. If the scrunch persists past six months or is accompanied by other concerning signs, talk to your pediatrician.

Your baby’s doctor knows your child’s specific development pattern — if you’re unsure whether the scrunch is still within the expected range, a quick check during a well-baby visit can confirm everything is on track.