SIDS and Hiccups

I am not aware of any research studies linking SIDS and hiccups.

Hiccups are basically an involuntary inspiratory spasm of the diaphragm. I suppose it is theoretically possible that such an abrupt inspiration could draw enough negative inspiratory pressure (vacuum) to draw the epiglottis over the larynx, obstructing the airway. Continued inspiration against that occluded airway could generate a negative pressure (vacuum) in the airway, which might keep the epiglottis sealed to the larynx.

However, when we (or babies) normally take a breath, there are synchronous neural signals sent to the muscles of the upper airway. They contract, causing the size of the upper airway to enlarge, so that the airway remains open during inspiration. Since hiccups are 'natural' breaths (as opposed to breaths generated by a ventilator, for example), I would suspect that there is synchronous upper airway muscle contraction to keep the upper airway open. However, I do not know if this mechanism is intact with hiccups.

Thank you.

Tom Keens
Children's Hospital Los Angeles