Speech dysfluency variations across menstrual phases in adult women who stutter: A single-subject study

There has been a significant paucity of data on the variability of stuttering severity across the biological rhythms associated with sex steroid hormones. The menstrual cycle, a prominent infradian rhythm, provides a unique and naturalistic environment to investigate the impact of fluctuating sex steroid hormones on the severity of stuttering.

A withdrawal/reversal A₁B₁C₁A₂B₂C₂ single-subject design was employed, involving multiple daily assessments of stuttering severity across two consecutive menstrual cycles in adult women who stutter. Five adult women with confirmed developmental stuttering, regular menstrual cycles, and verified ovulation participated in the study. Participants self-rated their stuttering severity daily using a 10-point severity rating scale. Data were analyzed through a combination of visual analysis and effect size calculations.

An increase in self-reported stuttering severity was observed during the follicular phase compared to the preceding menstrual phase. Furthermore, stuttering severity decreased during the luteal phase relative to the preceding follicular phase. These patterns were replicated in most participants; however, replication was not uniform, and some individual cycles showed variability.

These findings indicate that the follicular phase is associated with increased self-reported stuttering severity in women who stutter, suggesting the influence of menstrual cycle phases on stuttering dynamics.