Women who light up may extinguish their chances of getting pregnant. A new study finds the habit hurts fertility even for women who aren't using their own eggs to conceive!
The study out of Portugal and Spain found much lower pregnancy rates among heavy smokers, classified as those who smoke 10 or more cigarettes a day, who underwent invitro fertilization, compared to women who smoked less.
According to researchers, the findings suggest heavy smoking impairs the ability of the uterus to receive donor eggs, and add to the evidence that cigarettes and conception don't mix.
Ironically, the heavy smokers who did conceive were more likely to have multiple births, a surprising finding that researchers say needs further study to confirm, but suggests that tobacco, while impairing fertility in most, may have the opposite effect in some.
It's estimated an average of 100,000 women undergo IVF therapy every year in this country.
The study, led by researchers at the IVI Clinic in Lisbon, published in the journal Human Reproduction, compared the pregnancy rates of smokers who used donated eggs in IVF with those who smoked fewer than 10 cigarettes a day or none at all. The scientists from Spain and Portugal investigated the first cycles of egg-donated IVF treatments at a Spanish clinic between 2002 and 2005. There were 741 cycles among light or non-smokers and 44 in those who smoked more than 10 cigarettes day. None of the prospective fathers were smokers, and none of the women who donated eggs smoked heavily. The non-heavy smokers had a significantly higher pregnancy rate, with over half becoming pregnant (52.2 per cent), compared with just over a third (34.1 per cent) of the heavy smokers," said lead researcher Dr Sergio Soares.