A new study found that women hoping to conceive through in vitro fertilization (IVF) should avoid secondhand smoke. The study found that secondhand smoke is just as powerful as direct smoking in hampering IVF success. Researchers studied the quality of embryos and implantation rates of 225 women who were either smokers, nonsmokers (not exposed to smoke), or "side-stream" smokers (nonsmoking women who lived with smokers). Although all 3 groups showed no differences in the quality of embryos, differences were noted in pregnancy and implantation rates between those exposed to smoke and those who avoided it. The rate of successful pregnancy in nonsmokers was ~48%, while those exposed to smoke, whether direct or indirect, had a success rate of 19% to 20%. The researchers added that nonsmokers achieved a 25% implantation rate; both groups exposed to smoke had a rate of only 12%.