While the commonly measured and validated measure of

testicular size remains more useful for counseling an individ-

ual man presenting for an infertility evaluation, AGD does

provide some discrimination. Indeed, the current report and

prior studies have demonstrated a relationship between AGD

and sperm production. As AGD can be measured earlier in life

than sperm production, AGD may provide an early window

into a man

’

s reproductive potential. While testis volume may

also be measured, cryptorchism may complicate estimation

early in life, especially among premature infants. Moreover,

a

c

e

b

d

f

Fig. 1

Receiver operating characteristic curves for AGD and total testis

volume when examining measures of male fertility. Analysis examines

the ability of genital measure to predict subfertility. Abnormal semen

parameters defined by WHO 5th edition of the manual on semen

analyses. Solid lines represent AGD. Dashed lines represent total testis

volume. AUC given in Table

3

. A. Fatherhood status (

n

=454). B.

Ejaculate volume (

n

=187). C. Sperm concentration (

n

=191). D. Sperm

motility (

n

=189). E. Total sperm count (

n

=186)

.F

.To

ta

lmo

t

i

lesperm

count (

n

=186)

482

J Assist Reprod Genet (2015) 32:479

–

484