Paternal Exposure to Non-essential Heavy Metal Affects Embryo Cleavage and Implantation in Intracytoplasmic Sperm Injection (ICSI) Cycles: Evidence for a Paradoxical Effect.

Although the adverse effects of non-essential heavy metals on semen quality have been demonstrated in experimental animal models and occupational human exposure studies, little is known about the reproductive efficiency of exposed sperm during the process of intracytoplasmic sperm injection (ICSI). Our study aims to evaluate the effect of paternal exposure to non-essential heavy metals on embryo efficiency outcomes (embryo cleavage, fragmentation, implantation, and live birth) in ICSI cycle. Ninety-five heterosexual couples who underwent 95 ICSI cycles and 78 fresh embryo transfers between January 2003 and December 2009 were evaluated. Men whose female partner was undergoing ICSI were asked to provide semen and blood samples. Heavy metal levels (Pb, Cd, As, Hg, Ba, and U) were analyzed using an ion-coupled plasma-mass spectrometry (ICP-MS; Agilent 7500 ce, Agilent Technologies, Germany) equipped with a cell dynamic range (CDR). Paternal exposure to trace heavy metals was found to influence intermediate reproductive endpoints in ICSI cycles. After adjusting for paternal and maternal confounders, paternal blood concentrations of Cd [-0.30(-0.11,-0.02)], As [-0.26(-0.16,-0.11)], and U [-0.22(-0.24,-0.02)] were inversely associated with embryo cell cleavage on day 3. Counterintuitively, paternal blood and semen Pb levels [0.26(0.01,0.22); 0.25(0.03,0.14)] as well as semen U levels [0.27(0.01,0.19)] were positively associated with the proportion of implanted embryos. There were no significant associations observed for clinical pregnancy and live birth rates with any paternal heavy metal concentrations in semen and blood. These findings highlight the importance of paternal health for embryo efficiency outcomes in ICSI treatment cycles and the need for more male partner inclusive counseling in fertility practice. They also underline a paradoxical positive association between some heavy metal pollutants at low exposure levels and reproductive outcomes.

Civil war and male infertility in Lebanon.

OBJECTIVE: To investigate the long-term impacts of the 15-year Lebanese civil war on male infertility. DESIGN: Clinic-based, case-control study, using reproductive history and risk factor interview data and laboratory-based semen analysis. SETTING: Two IVF clinics in Beirut, Lebanon, during an 8-month period (January-August 2003). PATIENT(S): One hundred twenty infertile male cases and 100 fertile male controls, distinguished by semen analysis and reproductive history. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Standard clinical semen analysis. RESULT(S): Infertile male cases were more likely than fertile controls to have lived through the Lebanese civil war and to have experienced war-related trauma (residence in bombing areas, participation in combat, injuries, kidnapping, and displacement from home). Cases had a 57% increase in their odds of exposure to civil war-related trauma. CONCLUSION(S): This case-control study demonstrates an association between the Lebanese civil war and male infertility. Wartime and postwar exposure to a number of potential reproductive risk factors-including toxins, injuries, and stress-is believed to be the main factor leading to this finding.

Occupational and environmental exposures to heavy metals: risk factors for male infertility in Lebanon?

A case-control study was conducted to examine whether occupational or environmental exposures, particularly to heavy metals, are associated with male infertility in Lebanon, a war-torn country with a history of environmental degradation. Seventy-four infertile cases and 76 fertile controls were selected from 2 major fertility clinics in Beirut. Data collection involved risk-factor interviews, semen analysis, and blood collection for heavy metal analysis. Multiple regression analysis showed that men with reported occupational exposures were twice as likely to be infertile as unexposed men. However, none of the subcategories of infertile men (based on semen analysis results) had significantly higher whole blood concentrations of heavy metals when compared to fertile controls. Blood concentrations were well within the range for referent populations of healthy individuals. Thus, despite Lebanon's poor record of occupational and environmental stewardship, exposure to metal pollutants does not appear to represent an important risk factor for male infertility.