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Influence of metals on in vitro sperm migration in the human cervical mucus.

Abstract The presence of metals, especially copper, in the cervical mucus inhibits and stops sperm penetration. The effects of copper, silver, zinc, nickel and gold in solid elementary form were studied using the Kremer technique. Metallic wires were placed in capillary tubes containing the mucus. The parameters evaluated were: penetration depth, penetration density, qualitative motility and proportion of motile forms. The results of 286 mucus samples containing the different metals were compared with 84 controls. Copper produces the greatest alterations of all four parameters. Migration is stopped within 60 minutes, the distance reached is consistently less than 4 cm, and sperm immobilization is total at 240 minutes. Silver and zinc also have a strong spermiostatic effect, but significantly less intense than copper. Nickel produces alterations only in the qualitative and proportional motility. Gold is practically ineffective on all parameters. Consideration of these findings as the basis for a locally acting contraceptive method is suggested.