Breast shield design impacts milk removal dynamics during pumping: a randomised controlled non-inferiority trial

Introduction While many studies have investigated the importance of optimizing pumping patterns for milk removal, the influence of breast shield design on milk removal has not been the focus of extensive investigation. This study aimed to determine the effectiveness of breast shields with either a 105° or a 90° flange opening angle on breast drainage and milk volume expressed during pumping. Material and methods This study was a cross‐over, randomized controlled non‐inferiority trial (Registration; NCT03091985). Mothers (n = 49) of breastfeeding infants participated in the study over two study sessions. Participants were randomly assigned to pump both breasts simultaneously for 15 minutes with either the 105° or 90° breast shield in the first session, and the other shield in the second session. Effectiveness (breast drainage) and efficiency (volume expressed) of both breast shields were assessed after 15 minutes of pumping. Intention‐to‐treat and per protocol analyses were performed to determine if the 105° breast shield was non‐inferior to the 90° breast shield for breast drainage and volume expressed. Perceived comfort was assessed via questionnaire. Results The 105° breast shield was both non‐inferior and superior compared to the standard 90° shield for breast drainage (intention‐to‐treat, 3.87% (0.01‐7.72), P = .049) and volume expressed (intention‐to‐treat, 9.14 mL (1.37‐16.91), P=.02). In addition, the 105° shield was rated as feeling more comfortable (P