title: Pumping human milk in the early postpartum period: its impact on long-term practices for feeding at the breast and exclusively feeding human milk in a longitudinal survey cohort.
abstract: Most American mothers who feed human milk (HM) now use pumps to produce some of the HM they feed. Pumping is nationally recommended, but associations between pumping and HM-feeding durations are unknown.
  
  
  
  We examined whether and how the pumping frequency and types of reasons for pumping between 1.5 and 4.5 mo postpartum are associated with HM-feeding durations. We classified pumping reasons as nonelective [e.g., because of a difficulty feeding at the breast (FAB)] or elective (e.g., to produce HM to mix with solids). We hypothesized that women who pumped more frequently or nonelectively would have shorter HM-feeding durations.
  
  
  
  We used data from 1116 mothers in a longitudinal cohort who fed and pumped HM 1.5-4.5 mo postpartum. We used χ(2) and Cox proportional hazards regression models to examine the survival of any HM feeding, exclusive HM feeding, and FAB.
  
  
  
  Compared with mothers who pumped for elective reasons, mothers who reported one nonelective reason had greater hazards of stopping feeding any HM (HR: 1.12; 95% CI: 1.05, 1.21) or exclusive HM (HR: 1.14; 95% CI: 1.09, 1.20) and of stopping FAB (HR: 2.07; 95% CI: 1.77, 2.42). Mothers who pumped most frequently had the highest mean hazards of stopping feeding any HM (HR: 1.82; 95% CI: 1.68, 1.93) and feeding exclusive HM (HR: 1.21; 95% CI: 1.14, 1.26). Hazards of stopping FAB varied across the year. Compared with the least-frequent pumpers, the most-frequent pumpers had a 2.6-fold higher hazard of stopping FAB at 3 mo postpartum and a 1.7-fold higher hazard at 6 mo postpartum.
  
  
  
  Nonelective pumping reasons and higher pumping frequency were associated with shorter HM-feeding durations. Mothers who report that they use a breast pump for reasons related to either employment or FAB difficulty and their infants may be more vulnerable to risks associated with a shorter HM-feeding duration.
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY jpf99@cornell.edu.
authors.forename: Julia P
authors.identifier: 0000-0002-1038-0727
authors.initials: JP
authors.lastname: Felice
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY.
authors.forename: Patricia A
authors.identifier: 0000-0003-4827-5073
authors.initials: PA
authors.lastname: Cassano
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY.
authors.forename: Kathleen M
authors.identifier: 0000-0003-2111-6478
authors.initials: KM
authors.lastname: Rasmussen
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001903:Bottle Feeding; D001942:Breast Feeding; D061186:Breast Milk Expression; D005260:Female; D006801:Humans; D007223:Infant; D041943:Infant Formula; D007774:Lactation; D008137:Longitudinal Studies; D008895:Milk, Human / Q000737:chemistry*; D009035:Mothers; D049590:Postpartum Period; D016016:Proportional Hazards Models; D012959:Socioeconomic Factors; D013997:Time Factors; D055815:Young Adult
keywords: human milk; infant feeding; lactation; milk expression; pumping