Men that smoke, drink heavily or are exposed to pesticides while trying to have a baby could harm generations of offspring, according to specialists. The researchers studied animals and found abnormalities caused by environmental toxins that were produced by genetic changes passed on through generations. Smoking, drinking alcohol and consuming cocaine were found to cause chemical changes to semen.

“If I were a young man I would not drink heavily and I would not be smoking two packs of cigarettes per day while trying to conceive a child”, said Dr Cynthia Daniels of Rutgers University. “Studies have shown significant associations between male toxic exposures and increased rates of infertility, miscarriage, stillbirth and childhood health problems”, continued Dr Daniels.

A study carried out by Dr Matthew Anway, of the University of Idaho, USA, showed that the genetic changes caused by a pesticide, injected on female rats daily while pregnant, were passed on through four generations when the male offspring mated with healthy females.

Dr Anway said that “in addition to the spermatogenic and prostate abnormalities, trans-generational effects on numerous disease states were observed, including tumour development and kidney disease.”

The specialist claimed that the doses used in the experiments exceeded the levels of those that humans could expect to be exposed to in the environment, but that the study was designed to show the way toxins could lead to inheritable abnormalities.

Dr Gladys Friedler, of the Boston University School of Medicine, said: “Both animal and epidemiological studies demonstrate that paternal exposure to a variety of potential toxins can adversely impact fetal development, produce a wide spectrum of deficits in offspring and be expressed in subsequent generations.”