An infant developing a flattened head, known as positional plagiocephaly or brachycephaly, is a common concern because a baby’s skull is soft and highly moldable during the first few months of life. This phenomenon, often called flat head syndrome, is typically benign and does not affect brain development. While placing babies to sleep on their backs significantly reduces the risk of Sudden Infant Death Syndrome (SIDS), this practice has led to an increase in these positional head shape changes. Proactive and consistent preventative measures, focused on varying the pressure points on the skull, are highly effective in promoting a naturally rounded head shape and avoiding the need for a corrective helmet.
Understanding Positional Head Shape Changes
A newborn’s skull consists of several plates of bone connected by flexible fibrous joints, which allows the head to pass through the birth canal and accommodates rapid brain growth. Because these plates are pliable, prolonged pressure on a single area from resting against a flat surface can quickly cause a flat spot to develop, often within the first four months. The two most common types of positional flattening are distinguished by where the pressure occurs.
Positional plagiocephaly is characterized by asymmetrical flattening on one side of the back of the head, causing the head to look slanted or lopsided when viewed from above. This flattening often results in the ear, forehead, and cheek on the affected side appearing more forward. In contrast, brachycephaly involves a flat spot across the entire back of the head, making the head appear wider than usual and sometimes causing the forehead to bulge. Both conditions are caused by external environmental factors, making them highly responsive to repositioning efforts.
Strategic Repositioning During Sleep and Holding
Repositioning strategies focus on relieving pressure from the flattened or at-risk area of the skull whenever the baby is on their back. While the baby must always be placed to sleep on their back for safety, slight adjustments to their orientation can encourage varied head turning. A simple technique is to alternate the end of the crib where the baby’s head is placed each night, encouraging the baby to turn their head toward the room or door.
Using visual stimuli is a key passive strategy during periods of rest. When the baby is lying down, positioning mobiles, toys, or points of interest to the side you want them to turn toward encourages them to look away from the flattened spot. Positioning devices, wedges, or soft bedding are not safe for sleep and must never be used in a crib. Repositioning must be parent-driven within the safe boundaries of a firm crib mattress.
Repositioning extends beyond the crib into daily activities, particularly holding and feeding times. Alternating which arm is used to hold the baby during feeding naturally encourages the infant to turn their head to the opposite side to face the parent. Switching sides when carrying the baby—such as using a “football hold” or carrying them over the shoulder—relieves pressure on the back of the head while promoting balanced neck muscle development. Limiting the time a baby spends in carriers, swings, or car seats outside of necessary travel is important, as these devices keep the head in a fixed position against a hard surface.
Integrating and Maximizing Active Tummy Time
Tummy Time is the most important proactive measure for both preventing and correcting positional flattening. This activity removes pressure from the back of the head while strengthening the neck, shoulder, and upper body muscles. Developing this strength gives the baby the control needed to independently lift and turn their head while on their back, reducing the likelihood of a positional preference.
Tummy Time should be introduced early, starting with short sessions of three to five minutes, two to three times a day, even in the first few days of life. For newborns who resist, starting on the parent’s chest while the parent is reclined is a comforting way to begin. The goal is to gradually increase the frequency and duration, aiming for 15 to 30 total minutes of Tummy Time daily by about two months of age.
Engagement is key to maximizing Tummy Time. Placing a mirror, colorful toys, or the parent’s face directly in front of the baby encourages them to lift their head and engage their neck muscles. For babies who struggle, placing a rolled towel or small cushion under their chest can provide slight elevation, making it easier to sustain the position. Integrating short bursts of Tummy Time into the daily routine—such as after every diaper change—helps ensure consistency.
Identifying When Professional Consultation is Necessary
While repositioning and Tummy Time are effective for most cases, parents should monitor for signs that a professional evaluation is needed, as early intervention offers the best outcome. The most significant warning sign is a persistent head turning preference, where the baby consistently favors turning their head to one side and resists turning to the other. This preference may indicate congenital muscular Torticollis, a muscle tightness in the neck that both causes and exacerbates the flattening.
If noticeable asymmetry or flattening persists or worsens after several weeks of rigorous repositioning, a consultation with a pediatrician is warranted. The pediatrician can rule out rare conditions and provide a formal diagnosis, often including a referral to a pediatric physical therapist (PT). Physical therapy is the standard first-line treatment for positional issues and Torticollis, focusing on gentle stretching and positioning exercises to restore full range of motion. Addressing underlying muscle tightness through PT often corrects the head shape and prevents the need for a cranial remolding helmet.