<b>Background:</b> The cough reflex in childbearing women has been found to be more sensitive to chemical stimuli than that in other populations. However, the effect of age and sex on the cough reflex threshold (CRT) triggered by mechanical stimuli has not been studied. <b>Aim:</b> Our objective was to explore the association between age and sex, and CRT triggered by mechanical stimuli (air pulses) in childbearing women using a previously validated laryngopharyngeal endoscopic esthesiometer and laser rangefinder (LPEER). <b>Methods:</b> A cohort of 118 subjects, half of whom were female (49%), aged 19-95 years (a mean of 55.7 years), were prospectively recruited from two tertiary care university hospitals. Subjects with upper aerodigestive symptoms, i.e., dysphagia, rhinitis, cough and gastroesophageal reflux (GER), and healthy subjects, were included. Factors that could potentially influence CRT were clinically assessed using standard case report forms and fibreoptic endoscopy. Dysphagia was evaluated using a fibreoptic endoscopic evaluation of swallowing. CRT was measured by delivering air pulses of increasing intensity to the aryepiglottic folds of the subjects using the LPEER connected to a thin fibreoptic bronchoscope. Multiple linear regression was performed adjusting for confounders. <b>Results:</b> The CRT curve between childbearing women and males of reproductive age deviated extensively, only converging after the age of 50 years. Female sex (p<0.01) and childbearing age (p<0.01) were independently associated with lower CRT after adjusting for confounders. <b>Conclusions:</b> We found a lower mechanical CRT (increased sensitisation) in childbearing women, which could be protective against GER during pregnancy.
