Mendiola, J., Stahlhut, R. W., Jørgensen, N., Liu, F., & Swan, S. H. (2011). Shorter anogenital distance predicts poorer semen quality in young men in Rochester, New York. Environmental health perspectives. https://doi.org/10.1289/ehp.1103421
Mendiola J, Stahlhut RW, Jørgensen N, Liu F, Swan SH. Shorter anogenital distance predicts poorer semen quality in young men in Rochester, New York. Environmental health perspectives. 2011. doi:10.1289/ehp.1103421
Mendiola, J., et al. "Shorter anogenital distance predicts poorer semen quality in young men in Rochester, New York." Environmental health perspectives, 2011.
Young men with shorter anogenital distance had poorer semen quality
In a cross-sectional study of 126 young men in Rochester, New York, a shorter distance from the anus to the scrotum went with poorer sperm concentration, movement and shape. Among these men, those whose distance fell under the median had a 7.3 times greater likelihood of low sperm concentration.
Key Findings
Men with a shorter anus-to-scrotum distance had lower sperm concentration, motility and normal shape, and lower total sperm and motile sperm counts (p-values 0.002 to 0.048).
The distance from the anus to the penis showed no such link with these measures, and neither distance was associated with semen volume.
Men whose anus-to-scrotum distance fell under the median had a 7.3 times greater likelihood of low sperm concentration (95% confidence interval, 2.5 to 21.6) than men above it.
In the best-fitting regression model, a shift from the 25th to the 75th percentile of anus-to-scrotum distance was associated with a rise in sperm concentration equal to 40.2% of the median.
Interpretation
The study measured both distances and semen quality at one visit in 126 volunteers aged 18 to 22, 81% of them Caucasian. The results are associations, adjusted for height, ethnicity, recruitment period and abstinence time. In rodents, the distance reflects androgen exposure in the womb. The authors suggest the distance may be a marker of that exposure in men. They note the group was small, narrow in age and ethnicity, and they call for confirmation in larger and more diverse groups.
RRM Context
Restorative reproductive medicine evaluates both partners. Semen quality helps explain why a couple is infertile. The study reports a quick physical measurement that varied with sperm quality in young men and that the authors propose may reflect hormone exposure before birth. Male factors then fall under the same cause-based question asked of women.
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
In male rodents, anogenital distance (AGD) provides a sensitive and continuous correlate of androgen exposure in the intrauterine environment and predicts later reproductive success. Some endocrine-disrupting chemicals can alter male reproductive tract development, including shortening AGD, in both rodents and humans. Whether AGD is related to semen quality in human is unknown.
Objective
We examined associations between AGD and semen parameters in adult males.
Methods
We used multiple regression analyses to model the relationships between sperm parameters and two alternative measures of AGD [from the anus to the posterior base of the scrotum (AGD(AS)) and to the cephalad insertion of the penis (AGD(AP))] in 126 volunteers in Rochester, New York.
Results
AGD(AS), but not AGD(AP), was associated with sperm concentration, motility, morphology, total sperm count, and total motile count (p-values, 0.002-0.048). Men with AGD(AS) below (vs. above) the median were 7.3 times more likely (95% confidence interval, 2.5-21.6) to have a low sperm concentration (< 20 × 10⁶/mL). For a typical study participant, sperm concentrations were 34.7 × 10⁶/mL and 51.6 × 10⁶/mL at the 25th and 75th percentiles of (adjusted) AGD(AS).
Conclusions
In our population, AGD(AS) was a strong correlate of all semen parameters and a predictor of low sperm concentration. In animals, male AGD at birth reflects androgen levels during the masculinization programming window and predicts adult AGD and reproductive function. Our results suggest, therefore, that the androgenic environment during early fetal life exerts a fundamental influence on both AGD and adult sperm counts in humans, as demonstrated in rodents.
Male Fertility › Male Endocrine and Genetic Factors › Male Hormonal Axis · Lifestyle and Environment › Environmental Exposures › Endocrine Disrupting Chemicals
Jaime Mendiola, Richard W Stahlhut, Niels Jørgensen, Fan Liu, Shanna H Swan
J Mendiola, Rick Stahlhut, Dick Stahlhut, Rich Stahlhut, R Stahlhut, N Jørgensen, F Liu, S Swan
PMID 21377950 21377950 DOI 10.1289/ehp.1103421 10.1289/ehp.1103421 Mendiola et al. 2011, Mendiola 2011
