REPRODUCTIVE PHYSIOLOGY AND DISEASE
Anogenital distance as a measure of human male fertility
Michael L. Eisenberg
&
Larry I. Lipshultz
Received: 5 November 2014 /Accepted: 11 December 2014 /Published online: 23 December 2014
#
Springer Science+Business Media New York 2014
Abstract
Purpose
In humans, recent studies have correlated anogenital
distance (AGD) in adult men to testicular function. While
studies of a group of men suggest an association, the utility
of AGD in an infertility evaluation remains uncertain. We
sought to determine the utility of AGD to predict male fertility.
Methods
Between 2010 and 2011, men were recruited at a
urology clinic to participate. AGD was measured using digital
calipers in men being evaluated at a urology clinic. ANOVA
and ROC analyses were used to determine correlations be-
tween AGD, fatherhood status, and semen parameters.
Results
In all, 473 men were included in the analysis
with a mean age of 43±13 years. Anogenital distance
was significantly longer in men with higher sperm con-
centration, total sperm count, and total motile sperm
count. In order to evaluate the discriminating ability of
AGD, ROC curves were created comparing AGD and
total testis volume. The area under the curve (AUC)
was significantly larger for total testis volume compared
to AGD when evaluating fertility (0.71 vs 0.63,
p
=
0.02). Similarly, there was a trend towards a higher
AUC for testis volume compared to AGD for sperm
concentration and total sperm count. Stratification of
men with long/short AGD and large/small testes also
did not improve the predictive value of AGD.
Conclusions
While AGD is associated with sperm production
on a population level, at the individual level the distinction
based AGD alone cannot accurately estimate the efficiency of
spermatogenesis.
Keywords
Genitalia
.
Humans
.
Infertility
.
Perineum
.
Sperm
Introduction
A sexually dimorphic measure of genital development under
hormonal influence, andogenital distance (AGD) was initially
studied in animals.[
1
–
3
] More recently, human studies have
also demonstrated that boys have longer perineal lengths (or
AGD) than girls.[
4
–
7
] Human studies have also linked adult
testicular function, as assessed by sperm and testoster-
one production, to AGD. [
8
–
10
]A
sAGDs
e
em
stob
e
constant across a man
’
s adult life, the clinical utility of
AGD has been suggested in studies of infertile men.[
11
]
AGD is shorter in men with spermatogenic failure com-
pared to genital duct obstruction in men presenting with
azoospermia.[
12
] In addition, a retrospective examina-
tion of men undergoing varicocelectomy demonstrated
that men with a longer AGD are more likely to benefit
from varicocele repair implying possible clinical utility
in patient counseling.[
13
]. Men with prostate cancer
also demonstrated a shorter AGD compared to a control
group also suggesting some clinical merit.[
14
]
However, the clinical utility of such measurements of
fetal androgen exposure remains unclear to men present-
ing for an infertility evaluation.[
15
] While testis volume
is routinely measured during a fertility evaluation, the
Capsule
In humans, recent studies have correlated anogenital distance
(AGD) in adult men to testicular function. While AGD is associated with
sperm production on a population level, at the individual level the
distinction based AGD alone cannot accurately estimate the efficiency
of spermatogenesis.
M. L. Eisenberg (
*
)
Department of Urology, Stanford University School of Medicine,
300 Pasteur Drive Standford, Palo Alto, CA, USA
e-mail: eisenberg@stanford.edu
L. I. Lipshultz
Division of Male Reproductive Medicine and Surgery, Scott
Department of Urology, Baylor College of Medicine, Houston, TX,
USA
J Assist Reprod Genet (2015) 32:479
–
484
DOI 10.1007/s10815-014-0410-1