Prevention of Postpartum Smoking Relapse and Related Health Consequences by Breastfeeding Promotion

PROJECT SUMMARY/ABSTRACT About 14% of U.S. mothers smoke before pregnancy, and 54% of them report quitting spontaneously during pregnancy. However, large numbers of mothers who quit during pregnancy return to smoking (“relapse”) after delivery, e.g., 45% and 81% relapse by 6 and 12 months postpartum, respectively. Postpartum smoking relapse not only limits the benefits of smoking abstinence to the mother, but also has serious negative consequences for child health and development through secondhand smoke exposure. There is only limited success in preventing long-term (9 months or longer) postpartum smoking relapse by existing interventions. Breastfeeding mothers tend to have a lower risk of postpartum smoking relapse than formula-feeding mothers, although the causality of this association is unclear. It is possible that ex-smoking mothers who are less likely to relapse choose to breastfeed longer. But the reverse may also be true, i.e., mothers who breastfeed may be less likely to relapse, partly due to the hormonal, emotional, and mother-infant relationship benefits resulting from breastfeeding. A randomized controlled trial to reduce postpartum smoking relapse by promoting breastfeeding may not only move the field forward by addressing the uncertainty of causality but also yield a new approach to reducing the large public health problem of postpartum smoking relapse. We propose a randomized controlled trial to reduce postpartum smoking relapse by breastfeeding promotion from late pregnancy to 12 months postpartum. We will enroll 280 pregnant mothers who successfully quit smoking during this pregnancy (=28 weeks). After the pre-test, participants who are still smoking abstinent will be randomized into either the breastfeeding intervention group (N=140) or the attention control group (N=140). The intervention group will receive a multicomponent intervention consisting of breastfeeding education, lactation counseling, social support, contingent financial incentives, and early limited formula milk via syringe feeding (optional for at-risk infants). The control group will receive counseling and support focusing on general infant care, with attention and monetary earnings similar to the intervention group. Both groups will receive usual care (i.e., information, education, and Quitline) for postpartum smoking relapse. The outcomes are postpartum smoking relapse, breastfeeding practices, and maternal and child health. Aim 1 is to examine the efficacy of breastfeeding promotion intervention on postpartum smoking relapse. Aim 2 is to examine potential mediating mechanisms: reductions in stress and negative affect, enhancing mother-infant bonding and maternal sensitivity, and maternal weight retention. Aim 3 is to assess the effects of breastfeeding promotion intervention on maternal and infant health among ex-smoking mothers. This innovative study can yield promising data to support a new intervention to prevent postpartum smoking relapse. It has the potential to reduce smoking-related harms to both the mother and the infant, maximize the protective effects of breastfeeding on infant health and development, and narrow health disparities.