Newborn Scrunch: What Is It And What Causes It?

Swaddled up like a little burrito, scrunched in tight from head to toe - no, this isn't a new yoga pose your fitness-crazed friend convinced you to try. It's the darling curled-up posture of a newborn baby. Fresh from the womb, these brand new humans haven't quite realized they have limbs that can unbend. No, their instinct is to recoil and scrunch, freezing up in that tucked position like tiny frightened pill bugs. Of course, we can't blame them - they've just emerged from the perfect climate-controlled conditions of the uterus into this bright, loud, dizzying world. Who could fault them for wanting to retreat into a tight little ball? But not to worry, parents, this newborn scrunch is simply an adorable and temporary phase. Give your little burrito a few days or weeks to unfurl and they'll soon be splaying those arms and legs without a care, ready to take on the world. The scrunch period simply means your sweetpea is still adjusting - soon they'll be uncurling those tiny toes and fingers to explore their strange new home.

In the paragraphs to come, we'll explore what exactly causes newborn scrunch and why your little one looks so crunched up in those early days after birth. 

• What is the newborn scrunch?
• Is newborn scrunch a phenomenon that occurs in all babies?
• Why do babies scrunch their bodies?
• What age do babies lose the newborn scrunch?
• Is the newborn scrunch safe?

What is the newborn scrunch?

The "newborn scrunch" refers to the reflexive posture assumed by infants shortly after birth, characterized by their arms and legs being folded tightly against the body in a curled-up position.

This curled posture occurs as babies adjust to life outside the womb. Within the uterus, a fetus is normally in a cramped position with limbs tucked in close for months. When born, their muscles and joints initially find the open space overwhelming.

The scrunch allows newborns to temporarily retain a womb-like hug as their immature nervous system accommodates to the new environment. It helps regulate body temperature and transition from fluid-to-air breathing until they strengthen.

Unlike crying or grasping reflexes which signal specific needs, the scrunch is thought to be more of an instinctive response during this fragile early period. It typically only lasts hours before babies start to slowly extend their tiny limbs and become more flexible.

In contrast, as infants mature their movements increase in range and purpose, from rooting to feeding to exploring with hands and eyes. But the transient newborn scrunch provides a unique glimpse into how the tiniest new life adjusts from a cozy hug to life's big wide world outside the safe confines of the uterus.

Is newborn scrunch a phenomenon that occurs in all babies?

No, the newborn scrunch is not a phenomenon that all babies will exhibit.

Some research and observations have found that only about 50-70% of newborns will display this curled posture with limbs drawn up against the body in the short period after birth.

For some infants, the arms and legs may relax and extend more rapidly compared to others. This could be influenced by factors such as:

The health of the mother and fetus during pregnancy, such as whether fetal growth and development were normal.

The birthing process. Babies delivered via cesarean section may react differently than vaginal births.

Individual differences. The level of neurological maturation and ability to adapt varies between each infant.

So in summary, while the newborn scrunch is commonly seen, not every newborn will assume this curled position as they adjust to life outside the womb. There is natural variation between babies in how quickly they transition from fetal to neonatal positioning.

Why do babies scrunch their bodies?

Here are some reasons why some newborn babies scrunch their bodies shortly after birth.

Transition from fetal positioning: In the womb, babies are curled up tightly in a fetal position with limited space to move. When they are no longer confined, their muscles initially reflexively curl as their bodies adjust to the new, more open environment outside the uterus.

Sensory overload: Emerging into the world with its new sights, sounds, textures, temperatures and gravity can be very overwhelming for babies whose sensory systems are still developing. Curling helps minimize stimulation during this period of adjustment.

Thermoregulation: The curled scrunch position conserves body heat and helps regulate temperature as babies transition from the womb's constant temperature to external fluctuations. It takes time for their thermal regulatory system to mature.

Moro reflex: The Moro reflex, also known as the startle reflex, is a normal newborn reflex that causes a baby to suddenly extend their arms and legs and then bring them back in, as if they are hugging themselves. This reflex can be triggered by sudden movements, loud noises, or changes in sensation and may lead to the scrunching posture.

Flexor reflexes: Newborns have strong flexor reflexes that cause them to flex their limbs, such as curling their fingers into fists or bending their arms and legs. These reflexes are essential for their early motor development.

Immature muscles and nervous system: Newborns have relatively undeveloped muscles and nervous systems. They lack the muscle strength and coordination to stretch out their limbs fully, which contributes to their curled-up appearance.

Comfort and security: The fetal position can provide a sense of comfort and security for newborns. It's a way for them to self-soothe and feel protected, especially when they are adjusting to the new environment outside the womb.

What age do babies lose the newborn scrunch?

Most babies will stop exhibiting the newborn scrunch, or curled up body position, within the first few hours or days after birth. Here are some more details on when it typically disappears.

Within the first 2 hours: Many infants will start to relax out of the scrunch and unfurl their limbs within the first 1-2 hours after delivery as they adjust to the outside world.

By 6 hours: Around 50-70% of newborns will have lost the curled up reflex by this point and be able to fully extend their arms and legs.

By 1-2 days: For the remaining babies that held onto the scrunch longer, most will be completely out of it within the first 48 hours after birth.

Rare after 3 days: It's unusual for a baby to still be scrunched up at 3 days old, though a very small percentage may retain subtle remnants a bit longer.

Gone by 1 week: By the time they reach 1 week of age, all healthy full-term newborns have developed enough neurologically and physiologically that the scrunch response is no longer observed.

So in summary, while each baby progresses at its own pace, the newborn scrunch protective reflex is a very temporary phenomenon that medical experts would expect to see disappear completely within the first week of the infant's life outside the womb.

Is the newborn scrunch safe? 

Yes, the newborn scrunch is generally considered safe for babies. Here are a few key points.

Normal reflex: The scrunched posture is an involuntary reflex newborns exhibit to feel secure during the adjustment after birth. It's a natural part of the birth process.

Protective instinct: Curling up in this way allows babies to shield their vital organs while their nervous system matures in the hours/days postpartum. It helps regulate body temperature as well.

Transient phase: For most babies, the scrunched reflex disappears within 2-6 hours as they acclimate to extrauterine life. Lingering much longer could indicate an issue requiring medical evaluation.

No distress signs: When scrunched, babies aren't actively crying or grimacing. They can still breathe and move normally. This suggests it's not painful or harmful in the short adjustment period.

Monitored by caregivers: Medical staff check for any signs of distress beyond the initial reflexive phase, like changes in breathing, skin color or feeding ability.

Provided the newborn is otherwise stable - pink color, steady respirations, normal movement/feeding - experts view the temporary scrunched posture itself as harmless and an expected part of the birth transition process. It allows small new lives a secure entry into the world outside the safe confines of the womb.