Semen parameter decline with advancing age: a cause for concern? - Fertility and Sterility

In a world with ever-increasing socioeconomic pressures, it is not surprising that couples are more frequently opting to delay parenthood to address the pressing issues of education and career development. For most couples, this delay is in an effort to provide financial stability to a growing family. However, such delays may also result in consequences in the form of fertility declines (in one or both partners), thus making the delayed pursuit of a family potentially more difficult and expensive (if medical intervention is required). While many couples are well aware of the abrupt, and often absolute, barrier to fertility that can come with advanced maternal age, many are less aware of data that suggest that paternal age can also impact fertility in a much more subtle but continuous fashion. For many years the study of paternal age and impacts on semen parameters has offered largely conflicting results, leaving care providers and the lay public to debate about the actual importance of paternal age. Adding to this hesitancy to give any weight to the impact of paternal age are many anecdotal stories describing men of advanced age fathering children. Thus, even if age impacts semen parameters, at least for some men it does not catastrophically impact the ability to father a child. Despite such anecdotes and the difficulty in determining the impact of age on the semen parameters themselves, there have been reports of very real declines in fertility in men of advanced age. As an example, it has been shown that men older than 45 take ～5 times as long to achieve a pregnancy as men less than 25 after controlling for female age (1x1Hassan, M.A. and Killick, S.R. Effect of male age on fertility: evidence for the decline in male fertility with increasing age. Fertil Steril. 2003; 79: 1520–1527 Abstract | Full Text | Full Text PDF | PubMed | Scopus (153) | Google ScholarSee all References)(1). A similar decrease in fecundity was identified in a large population study in 2000 that showed that (after adjusting for maternal age) men > 35 had a 50% lower chance of achieving a pregnancy in 12 months of attempting conception (2x2Ford, W.C., North, K., Taylor, H., Farrow, A., Hull, M.G., and Golding, J. Increasing paternal age is associated with delayed conception in a large population of fertile couples: evidence for declining fecundity in older men. The ALSPAC Study Team (Avon Longitudinal Study of Pregnancy and Childhood). Hum Reprod. 2000; 15: 1703–1708 Crossref | PubMed | Google ScholarSee all References)(2). From these studies it is clear that advanced paternal age