Researchers at the Center for Human Genetics at Boston University School of Medicine and at the University of Minnesota Cancer Center have demonstrated the presence of a tobacco-specific carcinogen in the amniotic fluid of fetuses whose mothers smoked. This is the first study showing the presence of a tobacco carcinogen in the fetus in early pregnancy. Results of their study are presented in the April issue of the journal Prenatal Diagnosis. The study compared amniotic fluids obtained during routine prenatal diagnostic studies of both smokers and non-smokers at 15 - 20 weeks' gestation. Of the 21 mothers who smoked, 52.4% of their fetuses had traces of the tobacco-specific carcinogen NNAL in their amniotic fluid, compared with only 6.7% of the 30 non-smokers.
"Our results show that carcinogens from cigarette smoke directly reach and/or are metabolized in the exposed fetus," said lead author Aubrey Milunsky, director of the Center for Human Genetics and professor of Human Genetics at Boston University School of Medicine. Other studies have shown the presence of tobacco-specific carcinogens in the urine of newborns whose mothers smoked cigarettes, but now we have demonstrated a tobacco-specific cancer-causing agent in and around the fetus in early pregnancy.
According to Milunsky, the presence of NNAL raises serious concerns about the long- term potential consequences of smoking during pregnancy, including cancer in later life. Maternal smoking in pregnancy is known to be associated with higher perinatal mortality rates, an increased rate of spontaneous abortion, lower birth weights, and an increased frequency of sudden infant death syndrome (SIDS).
