Does planning to mixed feed undermine breastfeeding?

Continued breastfeeding is important for infants' health, but it is unclear whether mixed feeding increases the risk of breastfeeding cessation. We aimed to explore associations of mixed feeding and lactation problems with early cessation of breastfeeding. We analysed data from mothers who completed the Scottish National Maternal and Infant Feeding Survey and had previously breastfed their infants. At age 8-12 weeks, mothers (N = 1974) reported their feeding history and intentions, lactation problems and reasons for giving formula milk. The main outcome measure was cessation of breastfeeding before 6-8 weeks and time to cessation. By 6 weeks, 65% had mixed fed at some point, 32% had ceased breastfeeding, 22% were currently mixed feeding and 46% were exclusively breastfeeding. Lactation problems before 2 weeks were common (65%), and strongly associated with stopping breastfeeding (relative risk [RR]: 3.23, 95% confidence interval [CI]: 2.0-5.3) and with mixed feeding (RR: 3.14, 95% CI: 2.5-4.0). However, even after adjustment for breastfeeding problems mothers who planned to mixed feed (RR: 3.39, 95% CI: 2.4-4.9) and those who introduced formula for practicalities (RR: 3.21, 95% CI: 2.3-4.4) were more likely to stop breastfeeding. These variables also predicted later lactation insufficiency (planned mixed feeding RR: 1.39, 95% CI: 1.0-2.0; formula for practicalities RR: 1.76, 95% CI: 1.3-2.3). Mothers who received specialist lactation support were less likely to cease breastfeeding (RR: 0.63, 95% CI: 0.5-0.9) but nonspecialist input was unrelated to risk of cessation (RR: 1.06, 95% CI: 0.2-4.9). In conclusion, choosing to mix feed an infant is strongly associated with stopping breastfeeding, even in the absence of lactation problems.