Pressure to provide milk among mothers of very low birth weight infants: an explorative study
Authors: Schwab Isabella , Dresbach Till , Ohnhäuser Tim , Horenkamp-Sonntag Dirk , Scholten Nadine ,   Neo-MILK, Müller Andreas , Hellmich Martin , Ernstmann Nicole , Hammer Antje , Eyssel Friederike , Kribs Angela , Köberlein-Neu Juliane , Lugani Katharina , Mildenberger Eva , Rüffer Jens Ulrich , Matthias Katja , Sunder-Plaßmann Anne , Wiesen Daniel , Klein Iris , Klein Melanie , Rupprecht Christoph , Schleich Laura , Beckmann Olaf , Kurz Anke 
Published: February 2024

Abstract
Background
Pump-dependent mothers of very low birth weight (VLBW, < 1500g) infants experience specific challenges achieving sufficient milk supply in the neonatal intensive care unit (NICU) and are therefore less frequently able to achieve (exclusive) breast milk feeding. Stress due to the limitations on participating in the infant’s care may contribute to this problem. Some explorative studies suggest that pressure to provide milk may be an additional stressor in mothers. However, the type of pressure to provide milk perceived by mothers of VLBW infants has rarely been examined.

Methods
A retrospective and anonymous questionnaire was conducted with mothers of VLBW infants aged 6 to 24 months at the time of data collection. Quantitative data and written comments were used to examine the mothers’ perceptions. Descriptive and bivariate tests (Spearman´s rho, Pearson’s chi2) were performed to show correlations between pressure to provide breast milk, parental stress (PSS:NICU: role alteration subscale), milk volume, and maternal factors. Pressure to provide milk was measured through two self-developed single items to differentiate between internal and external pressures.

Results
Data of n = 533 mothers of VLBW infants was analysed. More than 70% of the mothers agreed that they pressured themselves to provide milk for their infant. In contrast, 34% of the mothers agreed that they felt pressure from outside to provide milk. Higher milk volume 14 days post-partum was significantly correlated with less internal (Spearman´s rho = 0.2017, p = 0.000) and less external pressure to provide milk (Spearman´s rho = 0.2991; p = 0.000). Higher PSS:NICU parental role alteration scores were significantly correlated with more internal (Spearman´s rho = -0.2865, p = 0.000) and more external pressure to provide milk (Spearman´s rho = -0.1478; p = 0.002). Milk volume 14 days post-partum and the PSS:NICU were not significantly correlated (Spearman´s rho = -0.0190; p = 0.701). Qualitative analyses highlighted these results and enhanced the bidirectional relationships between maternal pressure to provide milk and milk volume.

Conclusions
Especially internal pressure to provide milk is perceived by many mothers, being mutually dependent on milk supply and parental stress. Pressure to provide milk may be an important factor to decrease maternal stress in the NICU and, therefore, lead to more positive pumping and breastfeeding experiences. More research and validated instruments are needed to adequately measure pressure to provide milk with its different psychological, social, and environmental dimensions.