Dioxin has been linked to diminished fertility and an increased risk of preterm birth in both male and female mice exposed in utero to this common environmental contaminant.
In 2011, Kaylon Bruner-Tran, Ph.D., Kevin Osteen,
Ph.D., and colleagues reported increased risk of preterm birth in
mating partners of exposed male mice even though the female mice were
not exposed to dioxin.
In a paper published last month by PLOS ONE,
they found that the increased risk of preterm birth was passed down two
generations, although the third generation was not directly exposed to
Since the placenta is largely derived from the male (the sperm), the
researchers examined the testicular environment in which the sperm
developed. Males destined to have partners delivering preterm had
excessive testicular inflammation, which negatively affected sperm
If these findings hold true in humans, intervention designed to
reduce preconception testicular inflammation may be a valuable tool to
reduce the overall incidence of preterm birth, the researchers
This research was supported by a grant from the National Institute for Environmental Health Sciences (ES014942) and by Vanderbilt University School of Medicine.