Stressful life events during pregnancy negatively affect maternal and infant outcomes including breastfeeding initiation. Their impact on breastfeeding duration is uncertain. Given breastfeeding's important health benefits we analyzed stressful life event types and cessation of any and exclusive breastfeeding by 4 and 13 weeks. Methods. We collected self-administered survey data at 57 months postpartum from over 700 primarily urban low-income US mothers. Data covered prepregnancy, prenatal, and postpartum periods including 14 stressful life events (categorized into financial, emotional, partner-associated, traumatic). Analyses included only mothers initiating breastfeeding (). Logistic regressions controlled for maternal characteristics including a breastfeeding plan. Results. All four stress categories were associated with shorter duration of any and exclusive breastfeeding. In the adjusted models, statistically significant relationships remained for financial stress (4 weeks cessation of any breastfeeding duration) and traumatic stress (13 weeks exclusive breastfeeding cessation). Controlling for stress, a longer breastfeeding plan was significantly associated with a shorter breastfeeding duration (all models) as was depression during pregnancy and current smoking (several models). Conclusions. Among low-income women, impact of stressful life events on cessation of breastfeeding may differ by stress type and interfere with achievement of breastfeeding goal. Among these stressed mothers, breastfeeding may serve as a coping mechanism.

Infrared (IR) analysis is an emerging technology that may be a useful tool for milk banks to manage the nutrient variability in donor human milk. To evaluate the accuracy, reliability, and comparability of commercial infrared analyzers for measuring human milk macronutrients in a milk bank setting. Three nonprofit milk banks received blinded test kits of human milk that had been assessed using reference methods. Four infrared instruments were used to measure macronutrients: 1 filtered mid-IR; 2 Fourier-transformed full-spectra mid-IR; and 1 near-IR. Twenty-five unique samples were read concurrently for the accuracy arm. An identical sample was read daily for one month for the reliability arm. R-square values describing relationships with reference methods for total fat, crude protein, and lactose, were as follows: filtered mid-IR (0.98, 0.94, 0.48); Fourier-transformed full-spectra mid-IR (0.97, 0.93, 0.36 for instrument 1) and (0.98, 0.98, 0.31 for instrument 2), near-IR (0.93, 0.93, 0.12). There was no significant difference between instruments for crude protein and total fat measurements. There were significant differences in carbohydrate measurements between instruments. Coefficients of variation for 1 month of daily measurements in the reliability arm were: filtered mid-IR (≤ 4.6%); Fourier-transformed full spectra mid-IR (≤ 1.7%); near-IR (≤ 5.1%). Infrared analysis is an accurate and reliable method for measuring crude protein and total fat in a milk bank setting. Carbohydrate measurements are less accurate and significantly different between instruments, which will likely lead to differences in derived calorie values.