Reliability of Maternal Recall of Feeding at the Breast and Breast Milk Expression 6 Years After Delivery

Abstract

Background:

The reliability of long-term maternal recall of breastfeeding has been assessed previously, but not maternal milk expression (pumping) and child consumption of expressed milk.

Objective:

To examine the reliability of maternal recall of feeding at the breast, maternal milk expression, and child consumption of expressed milk 6 years after delivery using the Brief Breastfeeding and Milk Expression Recall Survey (BaByMERS).

Methods:

At 12 months postpartum, women who delivered a singleton, live-born infant at >24 weeks of gestation at a major U.S. academic hospital completed BaByMERS. Five years later, they were recontacted to complete the same questionnaire. Kappa statistics (κ), intraclass correlation coefficient (ICC), and Bland/Altman plots examined agreement. Sociodemographics were examined through stratified comparisons.

Results:

Of 299 women who completed both questionnaires, 35% had a postgraduate education and 82% identified as white/Caucasian. Kappa statistics showed substantial agreement for ever breastfeeding or feeding breast milk (combined) (κ = 0.71, 95% confidence interval [CI]: 0.44–0.98) and ever feeding at the breast (κ = 0.76, 95% CI: 0.62–0.89). Recall for duration of feeding at the breast was excellent (ICC = 0.96, 95% CI: 0.95–0.97), and of maternal milk expression was slightly less so (ICC = 0.83, 95% CI: 0.80–0.97). Maternal minority race/ethnicity, lower educational attainment, unmarried marital status, public/no health insurance, and smoking were associated with lower reliability; these differences were usually small and not consistent across all feeding practices.

Conclusions:

Maternal recall of contemporary lactation and infant feeding using BaByMERS was strongly reliable 6 years after delivery. BaByMERS may be useful to collect recall data, with attention to subpopulations that may exhibit lower recall reliability.