A new study using laboratory rats provides strong evidence that smoking during pregnancy can have lasting harmful effects on the developing heart.Scientists from the Center for Perinatal Biology,Loma Linda University,California found that adult offspring of laboratory rats who were exposed to nicotine prenatally showed clear signs of heart dysfunction."Our study shows that prenatal...nicotine has significant impact on cardiac function of adult offspring," Lubo Zhang said."The finding supports a very exciting area of research called 'fetal programming of cardiovascular disease,"Zhang said.