Changes in the rate of nicotine metabolism across pregnancy: a longitudinal study (original) (raw)

Increased nicotine metabolism during pregnancy could explain why nicotine replacement therapy (NRT) has not been found to be effective in pregnancy, but little is known about nicotine metabolism across pregnancy. This study was conducted to determine when changes in nicotine metabolism occur during pregnancy and to describe the magnitude of these changes. Longitudinal cohort study of pregnant smoker's nicotine metabolite ratio (NMR). Hospital antenatal clinics. 101 pregnant smokers were asked to provide saliva samples at 8-14 weeks (n = 98), 18-22 weeks (n = 65), 32-36 weeks gestation (n = 47), 4 weeks postpartum (n = 44) and 12 weeks postpartum (n = 47). Nicotine metabolite ratio (NMR) was measured using the ratio of cotinine to its primary metabolite trans-3'-hydroxycotinine. Multi-level modelling was used to detect any overall difference in NMR between time points. The 12 week postpartum NMR was compared with the NMR's collected antenatally and 4 weeks postpartum. NMR...