Brittany Collins Kaufman | January 20, 2017
Many parents know the frustration and misery of having an infant with colic. Try as they might, there often seems to be no way for concerned parents to calm a crying child. Though researchers haven’t been able to pinpoint the cause of colic — a commonly held belief is that it stems from a digestive issue — a research team has suggested that colic is rooted in the baby’s developing respiratory control system. The team also proposed that what causes an infant’s vulnerability to colic may be the same as what makes an infant at risk for sudden infant death syndrome (SIDS).
In a paper published recently in the journal Family Relations, lead researcher James McKenna, director of the Mother-Baby Behavioral Sleep Lab and Rev. Edmund P. Joyce, C.S.C., Professor of Anthropology at the University of Notre Dame, and his colleagues suggest that the origin of both colic and SIDS may be related to the gradual emergence of an infant’s ability to voluntarily control the release of air through the vocal tract, learned skills that are required for the development of speech. McKenna points out that infants are susceptible both to colic and SIDS during the same narrow developmental window, between about six to 14 weeks — the time period during which the respiratory system is learning how to shift between voluntary and involuntary control of breathing that involves both the “thinking” part of the brain (the cortex) and the brain stem.
For the first month or so of life, McKenna explains, the breathing process is controlled exclusively by the brain stem, with the infant having no control over vocalizing. But through about seven months of age, the brain stem becomes increasingly more functionally integrated with the cortex, essentially sharing the control of breathing between two sub-systems. During this less stable period of breathing control, infants are most susceptible either to colic or SIDS.