Association of Primary Language with Provision of Mother's Milk Among Very-Low-Birthweight Infants in Massachusetts.

Background: Racial/ethnic inequities in mother's milk provision for hospitalized preterm infants persist. The extent to which primary language contributes to these racial/ethnic inequities is unknown. Objective: Examine associations of maternal race/ethnicity and primary language with (1) any/exclusive mother's milk at hospital discharge and (2) the time to cessation of mother's milk provision during the hospitalization. Methods: We examined 652 mother/very-low-birthweight (VLBW) infant dyads at 9 level 3 neonatal intensive care units in Massachusetts from January 2017 to December 2018. We abstracted maternal race/ethnicity and language from medical records, and examined English and non-English-speaking non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic mothers of any race. We examined associations of race/ethnicity and language with (1) any/exclusive mother's milk at discharge (yes/no) using mixed-effects logistic regression and (2) cessation of mother's milk during the hospitalization using cox proportional hazard models, adjusting for gestational age, birthweight, and accounting for clustering by plurality and hospital. Results: Fifty-three percent were English-speaking NHW, 22% English-speaking NHB, 4% non-English-speaking NHB, 14% English-speaking Hispanic, and 7% non-English-speaking Hispanic. Compared with English-speaking NHW, NHB mothers (English adjusted odds ratio [aOR] 0.28 [0.17, 0.44]; and non-English-speaking aOR 0.55 [0.19, 0.98]), and non-English-speaking Hispanic mothers (aOR 0.29 [0.21, 0.87]) had lower odds of any mother's milk at discharge. In time-to-event analyses, non-English-speaking Hispanic (adjusted hazard ratio [aHR] 4.37 [2.20, 6.02]) and English-speaking NHB mothers (aHR 3.91 [1.41, 7.61] had the earliest cessation of mother's milk provision. Conclusion: In Massachusetts, maternal primary language was associated with inequities in mother's milk provision for VLBW infants with a differential effect for NHB and Hispanic mothers.