A Canadian Tertiary Care Centre Study of Maternal and Umbilical Cord Cotinine Levels as Markers of Smoking During Pregnancy: Relationship to Neonatal Effects

摘要

This study describes the prevalence of smoking among 3,220 pregnant women. Maternal and umbilical cord cotinine levels were compared with the women’s self-reported cigarette consumption, infant birth weight and antepartum and perinatal complications. Of the women who reported themselves as being active smokers (23%), 76% had a partner who smoked, and 38% reported exposure to environmental smoke in the workplace. Only 15% of nonsmokers had a partner who smoked, and 13% reported workplace exposure. The mean number of cigarettes/day was 20.5 (95% CI 19.6-21.4). The relative risk of having a small-for-gestational-age infant was significantly higher in smokers for mothers of both preterm (34-36 wks, RR= 3.38, 95% CI 1.25 - 9.16) and term babies (>- 37wks, RR= 2.04, 95% CI 1.58 - 2.63). Mean infant birth weight was 207 g lighter in the infants of smokers (p<0.001) and was inversely correlated to maternal serum cotinine level. Birth weight dropped by 0.99 g for every 1 ug/L increase in cotinine (r =-0.19, p<0.01).