New research by a team from the Department of Neurosurgery, School Medical at Ajou University in South Korea and published in the journal Medical Hypotheses, describes the actual process of birth this way:"Vaginal delivery is accomplished by the force of the labor overcoming the resistance forces of birth canal." These forces combine to produce the convex shape of the baby's head following natural childbirth. While a baby's skull is somewhat pliable to allow for these forces, researchers C.K. Oh and colleagues expressed concern that such forces could result in an incomplete skull fracture which can in turn have an impact on the brain and produce birth injury.
During the process of natural childbirth, the researchers wrote, "the fetal head passes through the birth canal and the skull receives pressure on the lateral aspect, resulting in molding, the convex shaping of the cranium.
"Also, the infant's skull is compressed by the mother's pelvic bony structures. These forces may lead to skull fractures and brain injuries. The hypothesis by the authors is that many skull fractures of the newborn present as incomplete fractures. The bony skull of the newborn is histologically primary bone tissue and which is incomplete in its ossification process. During birth the pressure forces upon the newborn's skull is gradual in one direction, rather than a sudden impact, and therefore it is thought that the skull fracture would be an incomplete fracture."
The authors of the study noted the difficulty in identifying incomplete fractures with standard X-rays. Therefore, it's possible that the incidence rate of skull fractures in newborns is higher than previously reported. "It is also probable that the external forces upon the skull that are sufficient to cause skull fractures, would also lead to significant brain injury more frequently than actually observed, and subsequently contribute to development of many brain disease later in children."
The authors of the birth injury study further state that "very close examination" should be used to determine the presence of brain injury or birth injury in babies who suffered incomplete skull fractures during the rigors of natural childbirth.
"The definitive diagnosis and treatment, as well as close follow up of patients with brain injury will assist the clinician in determining the causes of neurological diseases especially in those with previously unknown etiologies, which may be due to birth injuries," the researchers concluded.