Evaluation of patient compliance with the use of scrotal cooling devices.

Plain-language summary

This study set out to find out whether men actually use scrotal cooling devices as directed, and what happened to their semen results when they did. Forty men attending a single fertility clinic in Toronto, all with primary infertility and abnormal semen results, were given one of two commercially available cooling devices according to their own preference, and were measured again after four to twelve weeks. Two things improved. The share of sperm moving rose from 25.4% to 29.0%, and the share still alive rose from 64.8% to 71.7%. Concentration, total count, progressive movement, normal shape and DNA fragmentation (breaks in the genetic material inside sperm, where more breaks mean a lower chance of conception) did not show a significant change. Of the hormones, only prolactin (a pituitary hormone that lowers testosterone when it runs high, so a steady level means it is not interfering) moved. The compliance result is what the paper is about. Twenty-six of the forty returned the questionnaire, most of them had worn the device for less than the recommended time, and the reasons were practical rather than medical: it was uncomfortable, it got in the way of work, and it lost its cooling quickly.

Key findings

• Sperm motility rose from 25.4% to 29.0%, a significant change.
• Sperm vitality, the share of sperm still alive, rose from 64.8% to 71.7%, a significant change.
• Sperm concentration, total count, progressive movement, normal shape and DNA fragmentation did not show a significant change.
• Prolactin rose from 9.2 to 12.5 ng/mL, the only hormone that moved, and what that means here is unclear.
• 26 of the 40 men returned the questionnaire, and 76.9% of those who did used the device for less than the recommended time.
• The reasons they gave were discomfort (31.5%), interference with work (21.0%) and the device losing its cooling quickly (14.3%).