Prevalence, Correlates and Outcomes of Smoking in Pregnant Women with HIV: A National Observational Study in Italy.

Background: Few studies have evaluated in pregnant women with HIV the prevalence of smoking and its associations with maternal and neonatal outcomes. Objectives: to assess the prevalence of smoking among women with HIV in early pregnancy and the association between smoking and pregnancy outcomes in this particular population. Methods: We used data from a multicenter observational study to define the prevalence of smoking in women with HIV in early pregnancy, and the role of smoking status and intensity as risk factors for adverse maternal and neonatal outcomes. Main outcome measures were fetal growth restriction [FGR], preterm delivery [PD] and low birthweight [LB], evaluated in univariate and multivariate analyses. Results: The overall (2001-2018) prevalence of reported smoking (at least one cigarette/day) was 25.6% (792/3097), with a significant decrease in recent years (19.0% in 2013-2018). Women who smoked were less commonly African, had lower body mass index, older age, a longer history of HIV infection and higher CD4 counts. In univariate analyses, smokers were significantly more likely to have PD, LB, FGR and detectable HIV viral load at third trimester. Multivariable analyses confirmed for smokers a significantly higher risk of LB (adjusted odds ratio [AOR]: 1.69, 95%CI 1.22-2.34) and FGR (AOR 1.88, 95%CI 1.27-2.80), while the associations with detectable HIV and PD were not maintained. Conclusions: The common prevalence of smoking among pregnant women with HIV and its association with adverse outcomes indicates that smoking cessation programs in this population may have a significant impact on neonatal and maternal health.