Maternal smoked tobacco use is the most reported risk factor associated with adverse fetal outcomes. In Australia, data collected at antenatal visits focuses on maternal smoking and does not report other forms of tobacco and nicotine use (i.e. e-cigarettes and vaping) or cannabis use. Second-hand exposure to tobacco or cannabis smoke and vape aerosols are also unreported. Our research objective was to consider the impact of tobacco, nicotine, and cannabis (TNC) use and exposure on both placental and fetal outcomes.
This was a prospective observational study co-designed with the Australian Indigenous Butchulla people. Eighty-three families and close house-hold contacts who met the inclusion criteria of expecting an Australian Indigenous baby were enrolled between June 2022 and June 2023. TNC use and exposure was assessed at each antenatal visit using a bespoke NOTICE (NicOTine, tobacco and Cannabis use and Exposure) survey. Pathology reports were generated for all collected placentas after delivery and considered together with fetal outcomes.
Placental pathology reports (n=66) indicated a higher incidence of placental abnormalities (e.g., chorioamnionitis, circumvallate membranes, marginal or furcate cord insertion) in the exposed group than in the non-exposed group. Macroscopic changes in the placenta were evident in exposed placentas (43%) and some non-exposed placentas. Fetal malperfusion was reported in the exposed group (14%) and in the non-exposed group (9%). Mean gestational length was the same in both groups, however, the exposed group had a lower mean birthweight compared with the non-exposed group (Mann-Whitney, p < 0.05).
Gestational TNC exposure resulted in highly varied placental pathologies which were associated with adverse fetal outcomes. Given global shifts in smoking behaviours it is critical that we understand how all types of TNC exposure may impact fetal and maternal health, and we propose that this can be achieved through targeted collective work based on yarning and learning.