Human Reproduction, Vol. 18, No. 2, 374-383,
February 2003
© 2003 European Society of Human Reproduction and Embryology
Increased seminal plasma lead levels adversely affect the fertility potential of sperm in IVF
1 Fertility Research Laboratories, North Shore–Long Island Jewish Research Institute, Manhasset, NY, 2 Departments of Obstetrics and Gynecology and Cell Biology, New University School of Medicine, New York, NY, 3 Departments of Obstetrics and Gynecology and Urology, University of Rochester Medical School, Rochester, NY, 4 Biostatistics Unit, North Shore–Long Island Jewish Research Institute and Department of Public Health, Cornell University Medical College, New York, NY and 5 Division of Urology, Robert Wood Johnson Medical School, Camden, NJ, USA
6 Current address: Reproductive Medicine Associates of New York and New Jersey, New York City, NY and Morristown, NJ, USA
7 To whom correspondence should be addressed at: North Shore–Long Island Jewish Research Institute, 350 Community Drive, Room 125, Manhasset, NY 11030, USA. e-mail: sbenoff{at}nshs.edu
BACKGROUND: Lead remains in high levels in the environment and is known to reduce fertility in animal models, but a direct link between lead exposures and human infertility has not yet been established. METHODS: In a prospective, double-blind study of the metal ion levels and sperm function, semen was obtained from partners of 140 consecutive women undergoing their first IVF cycle. Lead in seminal plasma was determined by atomic absorption spectroscopy. Motile sperm populations were assessed for surface receptors for mannose binding, and the ability to undergo premature (‘spontaneous’), and free mannose-induced acrosome reactions. Fertile donor (n = 9) sperm were exposed to exogenous lead during capacitating incubations and then assessed for mannose receptor expression and acrosome loss. RESULTS: Lead levels were negatively correlated with IVF rates. Lead levels were negatively correlated to two of the three sperm function biomarkers (mannose receptors, mannose-induced acrosome reactions). Lead levels positively correlated with the spontaneous acrosome reaction. These findings were mimicked by in-vitro exposure of fertile donor sperm to lead. CONCLUSIONS: Multiple sperm parameters are affected as lead levels rise. Increased lead levels may contribute to the production of unexplained male infertility.
Key words: acrosome reaction/atomic absorption spectroscopy/IVF/male infertility/seminal plasma lead