Correction of first trimester biochemical aneuploidy screening markers for smoking status: influence of gestational age, maternal ethnicity and cigarette dosage

摘要

Objective To examine the gestational age, maternal ethnicity and cigarette dosage effects of the reduction of maternal serum pregnancy-associated plasma protein A (PAPP-A) and free- human chorionic gonadotrophin (free hCG) in smokers. Methods Maternal serum PAPP-A and free hCG corrected for confounders, excluding smoking, in first trimester smokers and nonsmokers were compared by gestational age, maternal ethnicity and cigarette dosage. A small set of second trimester smokers and nonsmoker controls were analysed for PAPP-A along with free hCG and assessed for gestational age effects of smoking. Results Pregnancy-associated plasma protein A reduction by smoking in the first trimester was not influenced by gestational age, however free hCG levels were only significantly reduced in weeks 12 and 13 in smokers. Ethnicity and cigarette dosage were also found to influence the reduction of both makers in smokers in the first trimester. In second trimester smokers, PAPP-A was found to be reduced by less and free hCG reduced by more than in the first trimester, although no second trimester gestational age effect on smoking was found. Conclusions Current methods of correcting for smoking status may be an oversimplification of a more complex subject. (c) 2012 John Wiley & Sons, Ltd.