Stereological analysis of the human testis after vasectomy indicates impairment of spermatogenic efficiency with increasing obstructive interval  Daniel Raleigh, B.Sc.Hons., Liza O'Donnell, Ph.D., Graeme J Southwick, M.D., David M de Kretser, M.D., Robert I McLachlan, M.D., Ph.D.  Fertility and Sterility  Volume 81, Issue 6, Pages 1595-1603 (June 2004) DOI: 10.1016/j.fertnstert.2003.10.046

FIGURE 1 (A) Correlation of testicular spermatid numbers (round–elongated spermatids, millions per gram of testis) with obstructive interval. Data from 34 vasectomized men (filled circles) and 10 control subjects (open circles) are shown. (B) Correlation of testicular fibrosis (percent of the testis with peritubular and interstitial fibrosis) with obstructive interval. Data from 27 vasectomized men (filled circles) and 5 control subjects (open circles) are shown. (C) Correlation of testicular spermatid numbers (millions per gram of testis) with total testicular fibrosis (percent of the testis with peritubular and interstitial fibrosis). Data from 27 vasectomized men (filled circles) and 5 control subjects (open circles) are shown. R = correlation coefficient, determined by Pearson product moment correlation. Raleigh. Vasectomy effects on human testis. Fertil Steril 2004. Fertility and Sterility 2004 81, 1595-1603DOI: (10.1016/j.fertnstert.2003.10.046)

FIGURE 2 (A) Correlation of serum FSH levels (IU/L) with obstructive interval in years and (B) correlation of serum FSH levels with age. Data from 32 vasectomized men (filled circles)and 5 control subjects (open circles) are shown. R = correlation coefficient, determined by Pearson product moment correlation. Raleigh. Vasectomy effects on human testis. Fertil Steril 2004. Fertility and Sterility 2004 81, 1595-1603DOI: (10.1016/j.fertnstert.2003.10.046)