Updated: Mar 25, 2019
In the pediatric wing of our clinic, we see may infants with torticollis and plagiocephaly as stated in the earlier blog, "It Won't Just Go Away!" In the last year or so, the numbers of babies with severe plagiocephaly (flattened or misshapen heads) is increasing and all share one common practice: these babies sleep in a Rock -n- Play instead of in a crib or bassinet. The pattern is so clear that it is time to speak out against this product.
When measuring plagiocephaly, we use digital calipers in our clinic to determine the cranial vault asymmetry, or difference from the right side to the left side of the skull. The "normal range" is a difference of less than 5 mm cranial differential with the protocol to monitor the head shape. Most babies who are referred to us have a cranial vault asymmetry on average of 9-10 mm asymmetry, moderate plagiocephaly, which requires intervention to correct. A conservative approach is used initially with a cranial remolding helmet a "last resort" once conservative measures have not produced the desired results by ~7 months old. The babies we are seeing who sleep in a Rock -n- play are arriving with an average of 12-13 mm cranial differential which is considered severe plagiocephaly. The report of sleeping in this device is consistent across the board with the more severe cases of head deformity seen clinically. These babies more often require cranial remolding helmets to correct the asymmetry because the initial plagiocephaly is so severe.
Most parents get angry and feel they have been duped once they learn that the Rock -n- Play is the cause of the severity of the baby's head shape because it is advertised as a "sleeper." Let me clarify by saying that not all babies who sleep in the Rock -n- Play end up with severe plagiocephaly, but the ones that we are seeing clinically with this diagnosis have a consistent pattern of sleeping in this device. By design, the Rock -n- play limits movement. The baby is strapped in a reclined position with two angled side seams where the baby rests the side of his or her head or rests the chin on the chest with the back of the head flat on the surface. A body at rest in a reclined position will seek out stability, so in the Rock -n- play, it is one of these two positions. Infants do not have the muscle strength to move out of confined positions that is why it is so important to monitor what they are sleeping on and rotate them regularly. Being strapped in a position in which the body weight is primarily on the bottom prevent the baby from moving freely.
A baby's soft spots are open until 12 to 18 months of age so during that time, the head is molding and changing shape. The sutures are open allowing the plates of the skull to move as the brain grows. It is vital to have equal contact on all parts of the head while the soft spots and sutures are open to ensure a round head shape. After the sutures and soft spots close, the head shape can only be changed surgically. This is the only window of opportunity you will have to shape your baby's head! If a baby sleeps through the night, that is 7-8 hours of laying in the same position on the same side of the head which will cause head flattening and deformation. My recommendation is a flat surface to allow baby to easily roll the head back and forth, wiggle the body in a natural movement. Without resistance from the sleep surface, this is much easier to do and much more natural. A body needs movement even when asleep. This movement and rotation of the head will help ensure a rounded head appearance. If you want something small and convenient to place next to your bed, look for something like this:
Many parents begin using a reclined sleeper (Rock -n- Play, swing, bouncer) because the baby has reflux. It is shown that a baby only needs to be inclined for 30 minutes to 1 hour after eating to reduce reflux so it is not necessary to keep the baby propped up all the time. Just as adults who experience reflux do not sleep sitting up, rather, wait for a period of time after eating before laying down. The same principle applies here for infants. If you feel the need to prop you baby up, put a wedge under the crib mattress to incline the surface so the baby is still free to move around during sleep, not confined or strapped in one spot all night long.
It is my mission to stop babies from sleeping in the Rock -n- Play as it is clinically proven to be a significant contributing factor in causing severe plagiocephaly. Please don't let your baby sleep in a Rock -n- Play. Send the manufacturers a message that this device should not be advertised as a sleeper!