If you're looking to make a baby, you might want to put out your cigarette before getting down to business: There's now more evidence linking smoking with decreased fertility in men and women — and their offspring.
A new study shows smoking by women during early pregnancy reduces the number of germ cells in the embryo. Germ cells later develop into eggs or sperm, so this reduction has the potential to reduce the baby's future fertility.
And men who smoke develop an imbalance in their levels of a protein, called protamine, that is vital to sperm fertility, another new study suggests.
The findings fall in line with past studies on the effects of smoking and secondhand smoke on fertility, researchers say. Research from the University of Buffalo in 2005 showed male smokers' sperm had a more difficult time binding to an egg than non-smokers' sperm. And research from the University of Rochester in 2008 showed that women who had been exposed to secondhand smoke as children or young adults were more likely to have trouble getting pregnant.
Germ cell study researcher Claus Yding Andersen of the University Hospital of Copenhagen said more research is needed to demonstrate whether the reductions in germ cells are permanent or are compensated for later in the pregnancy. Either way, he told MyHealthNewsDaily, "If women plan to get pregnant, this should be an incentive to quit smoking."
For male embryos, the number of germ cells was reduced by more than half when their mothers smoked during the first trimester of pregnancy, compared with mothers who didn't smoke at all, said Andersen. For all embryos, the reduction in germ cells averaged 41 percent.
And the more a mother smoked, the greater the reduction in the germ cells of her embryo, he said.