Men may think twice the next time they light up a cigarette after data released yesterday showed that heavy smokers reduce their chances of experiencing fatherhood. The Hellenic Society of Andrology (HSA) said that heavy smokers, those that puff three packets or more per day, have lower fertility rates. A smoker’s sperm will pierce the covering of the ovum with more difficulty in comparison with that of a non-smoker, said Nikos Sofikitis, HSA president. Embryos that have gone through fertilization by a smoker’s sperm have more growth problems, added Sofikitis, who blamed the nicotine in cigarettes for the difficulties. Scientists reached their conclusions after conducting tests on guinea pigs and human embryos. Greeks ranks among the European Union’s heaviest smokers with problems such as heart conditions remaining at alarmingly high levels. Sofikitis also advised couples who are trying to having children to try and solve any fertility problems before heading straight for in vitro fertilization.