Contraceptive efficacy of polyester-induced azoospermia in normal men

Contraception. 1992 May;45(5):439-51. doi: 10.1016/0010-7824(92)90157-o.


The contraceptive effect of a polyester sling applied to the scrotum was studied in 14 men. The suspensor was worn for 12 months. Follow-up investigations comprised periodic check of semen character, testicular size, rectal-testicular temperature difference, serum reproductive hormones and testicular biopsy. The electrostatic potentials generated by friction between the polyester suspensor and the scrotal skin were determined. Female partners used contraceptives until the men became azoospermic. After 12 months, the suspensor was abandoned and the aforementioned investigations were performed again. In the suspensor-wearing period, all men became azoospermic after a mean of 139.6 +/- 20.8 sd days, with decrease in both testicular volume (P less than 0.05) and rectal-testicular temperature difference (P less than 0.001). Serum reproductive hormones showed no significant change (P greater than 0.05). Seminiferous tubules revealed degenerative changes. No pregnancy occurred during this period. The polyester suspensor generated electrostatic potentials (mean 366.4 +/- 30.5 sd volt/cm2 by day and 158.3 +/- 13.6 sd volt/cm2 by night). In the suspensor-release period, the sperm concentration returned to the pre-test level in a mean period of 156.6 +/- 14.8 sd days. Likewise, the testicular volume and rectal-testicular temperature difference were normalized. The 5 couples, who had planned to become pregnant, conceived. The azoospermic effect of the polyester sling seems to be due to two mechanisms: 1) the creation of an electrostatic field across the intrascrotal structures, and 2) disordered thermoregulation. To conclude, fertile men can be rendered azoospermic by wearing the polyester sling. It is a safe, reversible, acceptable and inexpensive method of contraception in men.

PIP: Every 2 weeks, a physician at the Faculty of Medicine at Cairo University in Egypt examined 14 32-47 year old male volunteers wearing a polyester scrotal sling day and night for 12 months to determine if polyester fabrics can act as a contraceptive in men. They changed the sling only when it became dirty. None of the men dropped out of the study. The sling did not cause any complications or reactions. Their partners took an oral contraceptive until 3 sperm samples proved the men to be azoospermic. The men became azoospermic from 120-160 days (mean 139.6 days) after 1st putting on the sling. They remained azoospermic throughout the study. None of the partners became pregnant during the study. All 5 couples who wanted a pregnancy after the study period did indeed conceive. 4 had normal live births and 1 a miscarriage. The volume of their testicles fell greatly from 22.2-18.6 sd ml during the 12 months (p.05), but returned to pretest levels 75-135 days after removal. Further the mean rectal-testicular temperature difference was lower 3 months after wearing the sling than it was before they wore it (1.3-3 degrees Celsius; p.001). 3 months after they stopped wearing the sling, the mean rectal-testicular temperature difference reverted to normal. The polyester in the sling generated greater electrostatic potentials during the day than at night (326-395 volt/sq. cm. vs. 142-188 volt/sq. cm.; p.01). This was a result of the friction between the scrotum and the polyester sling. Germ cells of the seminiferous tubules still exhibited degenerative changes 6 months after removal of the sling. Within 140-170 days after removal, sperm concentration levels returned to pretest levels (40 million/ml). Apparently the electrostatic field effect and the disordered thermoregulatory effect of the polyester sling produced azoospermia. In conclusion, the sling is a safe, acceptable, inexpensive, and reversible method of contraception in men.

MeSH terms

  • Adult
  • Body Temperature Regulation / physiology
  • Contraceptive Devices, Male / standards*
  • Electricity / adverse effects
  • Epididymis / pathology
  • Epididymis / physiology
  • Humans
  • Male
  • Middle Aged
  • Oligospermia / chemically induced*
  • Oligospermia / pathology
  • Oligospermia / physiopathology
  • Polyesters / adverse effects*
  • Semen / physiology
  • Sperm Motility / physiology
  • Spermatozoa / pathology
  • Spermatozoa / physiology
  • Testis / pathology
  • Testis / physiology


  • Polyesters