The effect of paternal age on assisted reproduction outcome.

OBJECTIVE: To summarize the current knowledge about the association between paternal age and assisted reproductive technology (ART) outcomes. In contrast to the extensive investigation of the relationship between maternal age and the success of ART, there are few studies examining the effect of paternal age on ART outcomes.

DESIGN: Systematic review of the literature. By means of a PubMed literature search using the phrases "paternal age", "male age", and "assisted reproductive technology", we identified articles that investigated the role of male age in in vitro reproduction techniques.

RESULT(S): The 10 studies included in this review did not show a clear correlation between advanced paternal age and rates of fertilization, implantation, pregnancy, miscarriage, and live birth. Paternal age was not found to affect embryo quality at the cleavage stage (days 2-3). However, a significant decrease in blastocyst embryo formation was associated with increased paternal age, probably reflecting male genomic activation within the embryo. Except for volume, characteristics of semen such as motility, concentration, and morphology did not decrease with age.

CONCLUSION(S): There is insufficient evidence to demonstrate an unfavorable effect of paternal age on ART outcomes. Further study with well-defined entry criteria and uniform reporting of outcomes is needed to investigate the subject.