Higher blood nicotine concentrations following smokeless tobacco (pituri) and cigarette use linked to adverse pregnancy outcomes for central Australian Aboriginal pregnancies

Abstract

Background: In central Australia, Aboriginal women use wild tobacco plants, Nicotiana spp. (locally known as pituri) as a chewed smokeless tobacco, with this use continuing throughout pregnancy and lactation. Our aim was to describe the biological concentrations of nicotine and metabolites in samples from mothers and neonates and examine the relationships to maternal self-reported tobacco use, maternal and neonatal outcomes.Methods: Central Australian Aboriginal mothers (and their neonates) who planned to birth at the Alice Springs Hospital (Northern Territory, Australia) provided biological samples: maternal blood, arterial and venous cord blood, amniotic fluid, maternal and neonatal urine, and breast milk. These were analysed for concentrations of nicotine and five metabolites.Results: A sample of 73 women were enrolled who self-reported: no-tobacco use (n=31), tobacco chewing (n=19), or smoking (n=23). Not all biological samples were obtained from all mothers and neonates. In those where samples were available, higher total concentrations of nicotine and metabolites were found in the maternal plasma, urine, breast milk, cord bloods and Day 1 neonatal urine of chewers compared with smokers and no-tobacco users. Tobacco-exposed mothers (chewers and smokers) with elevated blood glucose had higher nicotine and metabolite concentrations than tobacco-exposed mothers without elevated glucose, and this was associated with increased neonatal birthweight. Neonates exposed to higher maternal nicotine levels were more likely to be admitted to Special Care Nursery. By Day 3, urinary concentrations in tobacco-exposed neonates had reduced from Day 1, although these remained higher than concentrations from neonates in the no-tobacco group.Conclusions: This research provides the first evidence that maternal pituri chewing results in high nicotine concentrations in both the mother and neonate and that exposure may be associated with adverse maternal and neonatal outcomes similar to those from smoked tobacco use in pregnancy. Screening for the use of a broader range of tobacco and nicotine products during pregnancy would provide a more inclusive assessment and contribute to a more accurate determination of tobacco exposure. This knowledge will better inform maternal and foetal care, and direct attention to targeted cessation strategies that are appropriate to the tobacco and nicotine use profile of the population.Note to readers: In this research, the central Australian Aboriginal women chose the term ‘Aboriginal’ to refer to themselves, and ‘Indigenous’ to refer to the broader group of Australian First Peoples. That choice has been maintained in the reporting of the research findings.