shortest AGD which appeared to drive much of the mea-

sured AGD difference between nonobstructive azoosper-

mic men and those with normal sperm production.

Certain limitations warrant mention. Working in a

referral center for male infertility, it was not always possi-

ble to blind observers to the men’s diagnoses, which theo-

retically may have led to observer bias. Because most of

the men with obstruction underwent vasectomy, the etiol-

ogy of azoospermia was not a diagnostic dilemma. It is

possible that men undergoing vasectomy are a population

distinct from men who have obstruction for other reasons

(e.g. CBAVD, idiopathic epididymal obstruction). Indeed,

men with CF (cystic ±brosis) have been shown to have

impaired testosterone production (Boas

et al.

, 1996).

Unfortunately, the limited numbers of men remaining

after strati±cation by obstructive diagnosis precluded

subanalyses. However, future work should validate the

utility of AGD in predicting azoospermia from all etiolo-

gies. While the measurements are similar to those from

our earlier studies, slight differences do exist as the cur-

rent report examines a distinct subpopulation (Eisenberg

et al.

, 2011, 2012).

Moreover, it is interesting to note that the men with

obstructive azoospermia were taller than the men with

nonobstructive azoospermia. This may have resulted by

chance alone, however, it may also re²ect subtle develop-

mental differences between the groups. In addition, there

were a limited number of noncaucasian men, preventing

racial subanalyses. Moreover, the current method of AGD

measurement in adult men has not been studied, and

thus its accuracy and reproducibility were dif±cult to

assess by means other than comparison of measurements

by investigators (Eisenberg

et al.

, 2011, 2012). However,

we have previously shown good correlation and reproduc-

ibility of our methods. Nevertheless, our study represents

the ±rst analysis of anogenital distance in azoospermic

adult men and suggests a clinical utility for the measure-

ment. As such, AGD may predict normal male genital

development and sperm production and could therefore

provide a novel metric to assess reproductive potential in

men. Moreover, it may give the practitioner additional

prognostic information when counseling azoospermic

men.

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