The effect of cigarette or sheesha smoking on first‐trimester markers of Down syndrome

Abstract

To investigate the influence of cigarette or sheesha smoking on first-trimester markers of Down syndrome. A prospective observational study. Primary care centres and antenatal clinics of Maternity and Children Hospital, King Abdulaziz University Hospital and New Jeddah Clinic Hospital, Jeddah, Saudi Arabia. Women with a singleton pregnancy who were either nonsmokers (n = 1736) or cigarette smokers (n = 420) or sheesha smokers (n = 181). Fetal nuchal translucency thickness (fetal NT), maternal serum free beta-human chorionic gonadotrophin (free beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) were measured at 11 weeks 0 days to 13 weeks 6 days of gestation in all women. Women were grouped according to smoking status, confirmed by maternal serum cotinine measurements, and analyte levels between groups were compared. Fetal NT, maternal serum free beta-hCG, PAPP-A and cotinine measurements. Compared with nonsmoking women, fetal NT was significantly increased and free beta-hCG and PAPP-A levels were significantly decreased in both cigarette and sheesha smokers. There were significant relationships between all three markers and the number of sheeshas consumed per day. Cigarette and sheesha smoking significantly affect first-trimester markers of Down syndrome (fetal NT, free beta-hCG and PAPP-A). Correction for this effect in women who smoke might improve the effectiveness of first-trimester screening for Down syndrome in these women. The underlying mechanism(s) relating smoking to the changes in first-trimester markers require further studies.