Integrating ultrasound biomechanics and clinical assessments to examine breastfeeding function: novel insights into tongue mobility, milk transfer, and reflux symptoms.

backgroundBreastfeeding is a dynamic co-occupation between mother and infant, influenced by both anatomical and functional factors. Tongue mobility plays a critical role and may impact infants' feeding efficiency and quality. Breastfeeding biomechanics, evaluated using tools such as ultrasound, and clinical aspects, assessed through questionnaires and examinations, have largely been studied independently. The aim of this study was to evaluate the association between breastfeeding biomechanics and clinical measurements of breastfeeding quality. Specifically, to assess the correlations between clinical aspects including Gastro-Esophageal Reflux (GER) symptoms, maternal nipple pain and mean milk transfer rate (MTR) with biomechanical measurements including distances and angles between the tongue, nipple, and hard-soft-palate-junction (HSPJ).

methodsA cross-sectional study was conducted in Israel including 21 mother-infant dyads (infants aged 3-6 weeks). Data collection included demographic questionnaires, clinical assessments of tongue mobility and breastfeeding self-efficacy, as well as real-time ultrasound imaging of the tongue and nipple during feeding. Mean milk transfer rate was measured by pre- and post-feed infant weight. Statistical analyses included Mann-Whitney tests, Spearman's correlations, and linear regression to explore associations between clinical and biomechanical parameters.

resultsMean milk transfer rate was significantly associated with ultrasound measurements, including tongue-nipple distances and angles, and maternal nipple pain scores (r and p 0.489, 0.029 and 0.593, 0.012, respectively). A transfer rate threshold of 4.5 g/min demarcated qualitative changes in the ultrasound measurements. Higher pain scores and restricted tongue mobility correlated with lower mean milk transfer rates (r and p 0.509, 0.036 and 0.558, 0.020 respectively). Gastroesophageal reflux symptoms were negatively correlated with nipple diameter changes during feeding (r=-0.598, p = 0.009).

conclusionsThis study highlights the interplay between breastfeeding biomechanics and clinical symptoms. Mean milk transfer rate, influenced by both maternal and infant factors, emerged as an indicator of breastfeeding quality. Our findings suggest a potential mechanistic link between feeding quality and the presence of gastroesophageal reflux symptoms. Incorporating time-based milk transfer assessments and ultrasound measurements into clinical practice may enhance diagnostic precision and therapeutic strategies. Clinicians are encouraged to assess breastfeeding quality in cases of reflux symptoms.