Is There Sperm in Pre-ejaculate? How to Study Pre-ejaculate to Determine Contraceptive Efficacy for Withdrawal [23I]

Abstract

INTRODUCTION: 

The perfect-use failure rate of withdrawal for contraception is not informed by controlled clinical trials, but rather inferred by the presumption of sperm in the pre-ejaculate. Several studies comprising a range of collection and examination methods provide contradictory data, highlighting the importance of a review that summarizes previous evaluation methods and defines optimized research methods.

METHODS: 

We included peer-reviewed literature indexed in PubMed, EMBASE, and Web of Science that evaluated the sperm content of pre-ejaculatory fluid as a defined outcome. Pre-ejaculate collection and evaluation methods were identified for each study, assessing strengths, limitations, and the validity of conclusions drawn from the findings. These findings were synthesized to provide optimal guidelines for evaluating the contributory risk of pre-ejaculate in contraceptive failure.

RESULTS: 

Of six human trials examining the sperm content of pre-ejaculatory fluid, three concluded that sperm was absent from their samples, however small sample size and selection bias were present. Four studies examined dried preparations, which could not evaluate motility nor measure volume. Only two differentiated between pre-ejaculate and ejaculate. No studies reported on participant characteristics or behavioral antecedents that might influence collection of an uncontaminated sample.

CONCLUSION: 

Previous pre-ejaculate research have methodological problems that limit the reliability of their findings. Future research should measure and examine wet and dry specimens, differentiate between pre-ejaculate and ejaculate, examine sperm for motility and concentration, as well as query for clinical factors associated with sperm leakage and presence in the pre-ejaculate. Findings via these methods will better inform guidance on pregnancy risk with pre-ejaculate and withdrawal.