Association between cigarette and heated tobacco use and breastfeeding cessation within 6 months postpartum in Japan: an internet-based cross-sectional study.

This study examined the association between cigarette and heated tobacco product (HTP) use before and during pregnancy and after six months postpartum and premature breastfeeding cessation (within 6 months postpartum). An internet-based cross-sectional survey was conducted from July to August 2021 in Japan, and the data of 4,005 women who gave birth between January 2019 and February 2021 were analyzed. The Poisson regression model with robust error variance showed that pre-pregnancy cigarette-only (adjusted prevalence ratio [aPR], 1.34; 95% confidence interval, [CI] 1.06 - 1.70) and combination users (i.e., cigarettes and HTPs) (aPR, 1.34; 95% CI, 1.02 - 1.77) and quitters during pregnancy (aPR, 1.37; 95% CI, 1.15 - 1.64) were more likely to cease breastfeeding prematurely than non-users. HTP-only users before (aPR, 1.32; 95% CI, 0.99 - 1.76) and during pregnancy (aPR, 1.08; 95% CI, 0.61 - 1.92) had no association with premature breastfeeding cessation. The multinomial logistic regression model showed that premature breastfeeding cessation was associated with cigarette-only (adjusted relative risk ratios [aRRR], 2.17; 95% CI, 1.22 - 3.85) and combination-use (aRRR, 2.62; 95% CI, 1.17 - 5.87) after 6 months postpartum. Women with cigarette or combination-use histories, despite quitting during pregnancy, tended to terminate breastfeeding prematurely, but this was not the case for HTP-only users.