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Post-Doctoral Fellowships
Male Fertility and Environmental Exposures
Male reproductive health and fertility is of considerable public health importance due to its high
medical, societal and economic burden and use as a predictor of morbidity and mortality. In
addition, male reproductive health and fertility is sensitive to the impacts of modern environment
on human health, such as exposures to endocrine disrupting chemicals (i.e. pesticides)
and could serve as a “canary in a coal mine”. There is growing evidence that there may be a
common environmental etiology for several male disorders such as reduced semen quality (SQ),
cryptorchidism, hypospadias and testicular cancer.
The statements of Carlsen et al. in 1992 and Swan et al. in 2000 that SQ had declined over the
past 50 years remain controversial. An evidence-based answer to this important question requires
rigorous scientific effort that takes into account all new data published since 1996 and synthesizes
it by proper analytical methods.
The aims of the current study will be to identify contemporary temporal trends and geographic
variability in sperm concentration and examine modification of temporal trends by geographic
location. We will conduct a systematic literature review and meta-analysis of all studies of semen
quality in populations unselected by fertility status published since 1996. From each study, we
will extract data on semen parameters, semen collection and analysis methods, temporal and
spatial variables, study population, study variables and quality, and personal variables. We will
use multiple complex analytical methods to model temporal changes. We will use stratified and
meta-regression methods to examine geographic variability, controlling for covariates. Interactions
between time and geographic region will be analyzed.
Fellow
Hagai Levine
Mount Sinai Hospital,
USA
Supervisor
Shanna Swan
2014-