Seminal lead concentrations negatively affect outcomes of artificial insemination  Susan Benoff, Ph.D., Ian R Hurley, Ph.D., Colleen Millan, M.A., Barbara Napolitano, M.A., Grace M Centola, Ph.D.  Fertility and Sterility  Volume 80, Issue 3, Pages 517-525 (September 2003) DOI: 10.1016/S0015-0282(03)00981-6

FIGURE 1 Prospective blinded analysis examining the relationship between seminal plasma lead levels and pregnancy rates after artificial insemination. The two parameters were negatively correlated. The solid line in the figure represents the regression line. Two donors with so-called normal seminal plasma lead levels and f rates of zero were subsequently identified as having an isolated defect in mannose receptor expression; these donors, identified by the asterisks, were removed from further study to eliminate a confounding variable. Benoff. Seminal plasma lead and artificial insemination.Fertil Steril 2003. Fertility and Sterility 2003 80, 517-525DOI: (10.1016/S0015-0282(03)00981-6)

FIGURE 2 Four of the 15 artificial insemination semen donors studied changed VGKC pharmacological phenotype over the 20-month study period. These men converted from charybdotoxin resistance (“Rr”; open bars) to charybdotoxin sensitivity (“Rs”; hatched bars) of the progesterone-stimulated acrosome reaction. (A), All four subjects exhibited a decrease in seminal plasma lead levels over time. The horizontal dashed line represents the threshold lead value (≤42.3 μg/dL) identified by Receiver Operating Characteristic curve analysis that discriminates between men likely to exhibit normal fertilization rates in IVF [i.e., ≥63% of metaphase II oocytes inseminated; (19)] from those likely to produce reduced or failed fertilization. (B), Cycle fecundity information was available for three of the four subjects; all displayed an upward trend in cycle fecundity rates. The horizontal dashed line indicates the IUI pregnancy rate from 2,351 consecutive cycles [“normal artificial insemination f rates” = ≥13.4%; (1)]. Benoff. Seminal plasma lead and artificial insemination.Fertil Steril 2003. Fertility and Sterility 2003 80, 517-525DOI: (10.1016/S0015-0282(03)00981-6)