Trajectories of Breastfeeding-Related Thoughts and Attitudes Among Low-Income Smoke-Exposed Pregnant Women: A Latent Class Growth Analysis

Background: Psychosocial predictors of breastfeeding and changes in those factors during pregnancy, along with the relationship of those changes with both breastfeeding and smoke use and exposure, are not well explored. Research Aim: The aim of this study was to identify distinct trajectories of psychosocial determinants of breastfeeding and smoking in pregnant women. Methods: We used a longitudinal study design and data from a randomized controlled trial conducted among smoke-exposed pregnant women and their infants. Participants were recruited early in pregnancy and were surveyed at ≤ 16 and 32 weeks gestation, delivery, 3 and 6 months postpartum for breastfeeding intentions, initiation, continuation, and smoke use and exposure. Psychosocial variables associated with breastfeeding were measured at baseline and 32 weeks gestation using the Mitra index, a structured questionnaire that assesses barriers and facilitators of breastfeeding intentions. Latent class growth analysis was performed using Mitra scores to identify distinct subgroups of participants with different trajectories. Sociodemographic characteristics, breastfeeding, and tobacco smoke use and exposure were compared across classes. Results: Three or four trajectories were identified for each of the six Mitra scores. Trajectories for all Mitra scores were associated with breastfeeding intention and initiation. Overall, Mitra, knowledge, self-efficacy, social support, and time barrier classes all differed by tobacco smoke use or exposure. Conclusion: Trajectories of breastfeeding knowledge, self-efficacy, social support, and time to breastfeed/social barriers are associated with tobacco smoke use and exposure during pregnancy. Encouragement to breastfeed and to cease and avoid tobacco smoke should start early in pregnancy, focusing on these determinants to improve health outcomes.