Male contraception development: monitoring effective spermatogenesis suppression utilizing a user-controlled sperm concentration test compared with standard semen analysis

Abstract

Objective: To determine whether a user-controlled sperm concentration test compared with standard semen analysis can effectively monitor spermatogenesis suppression for male contraception.

Design: Single center, prospective sub study of the ongoing clinical trial: "Study of daily application of Nestorone and testosterone combination gel for male contraception."

Setting: Research institute at an academic medical center.

Participant(s): Couples participating in the male contraceptive clinical trial.

Interventions: None.

Main outcome measure(s): The ability by participants to monitor sperm suppression to a threshold compatible with contraceptive efficacy utilizing a user-controlled test verified by sperm concentration determined by standard laboratory methods.

Result(s): Thirty-eight men participating in a hormonal male contraceptive clinical trial provided multiple samples during spermatogenesis suppression for this substudy. Participants, employing a user-controlled test, correctly identified the absence of sperm (a negative test) in 100% of their laboratory-confirmed azoospermic samples (n = 122). Participants also identified 100% of samples (n = 73) with sperm >0.2 million/mL as positive. Sperm counts between 0.01 and 0.2 million/mL were identified as negative in 96% of samples. Trial participants noted the overall ease of using the test with respect to sample preparation, test timing, and result interpretation, and that they could accurately use this test at home without difficulty.

Conclusion(s): Participants undergoing spermatogenesis suppression in a hormonal male contraceptive trial performed user-controlled test to determine whether their semen sperm concentration was ≤ or >0.2 million/mL. Compared with standard semen analyses, participants correctly identified 100% of samples with sperm counts >0.2 million/mL as positive (Sensitivity 100%). A positive result when the couple is using a male contraceptive method triggers the need for semen analysis by a laboratory while the couple uses another method of contraception. Participants correctly diagnosed samples ≤0.2 million sperm/mL as negative in 99% of samples (specificity 99%). A negative result indicates a sperm concentration ≤0.2 million/mL, well below the threshold of ≤1 million/mL offering contraceptive efficacy demonstrated by prior studies. At-home sperm concentration test would minimize the need for users to return to the clinic to monitor suppression of spermatogenesis, decreasing cost and burden of male contraception trials and increasing practicality of the method.

Clinical trial registration number: NCT: 03452111.

Trial registration: ClinicalTrials.gov NCT03452111.

Keywords: Male contraception; at-home sperm concentration test; hormonal male contraception; spermatogenesis suppression.