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

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.