Heavy Smoking May Hinder Uterine Receptiveness
Heavy smokers less likely to become pregnant, but more likely to conceive multiple children
THURSDAY, Nov. 9 (HealthDay News) -- Cigarette smoking may make the uterus less receptive to implantation, according to a report published online Nov. 9 in Human Reproduction.
Sergio Soares, M.D., of the IVI-Lisboa in Lisbon, Portugal, and colleagues analyzed results from all the first cycles of oocyte-donated in vitro fertilization treatments occurring in their clinic between January 2002 and June 2005. The cohort included 741 women who smoked fewer than 10 cigarettes a day and 44 heavy smokers who smoked more than 10 cigarettes a day. None of the women's partners or egg donors were heavy smokers.
Slightly more than 52 percent of the non-heavy smokers became pregnant, compared with 34.1 percent of the heavy smokers. Heavy smokers had a significantly higher rate of multiple pregnancies, compared with women who did not smoke as much (60 percent versus 31 percent). The researchers note that this seemingly counterintuitive finding requires further confirmation.
"We should now be telling patients if they are heavy smokers that even if fertilization takes place, they have less chance of achieving successful pregnancy, whether they are trying to conceive naturally, or through in vitro fertilization, and particularly with donated oocytes," Soares explained in a statement. "Furthermore, we should warn them of the risks of multiple births."