The oral feeding skills, feeding behaviours and choking prevalence of New Zealand infants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Health Science at Massey University, Albany, New Zealand

Abstract

Background: Oral feeding skills (OFS) are essential for infants and children to accept foods suitable for their age. Limited evidence indicates that, even without obvious medical issues, some healthy infants may experience subtle difficulties or delays in developing OFS, which can result in restricted food acceptance during infancy and later childhood. Distinguishing between normal developmental variation and a difficulty or delay in OFS has been challenging for health professionals. Early identification of OFS issues can help prevent problematic feeding behaviours, nutritional problems, and parental stress later in childhood. The complementary feeding period represents a crucial milestone and a vulnerable window for early feeding development. During this transition, parents often report challenging behaviours as infants encounter new tastes and textures, frequently without recognising potential underlying OFS difficulties. This developmental stage also aligns with an increased risk of choking. Food-related choking (FRC) poses a significant public health concern, particularly in infants under 12 months, whose developing anatomy and emerging OFS create physiological vulnerability. Complementary feeding practices may also be associated with FRC occurrence due to the varied approaches in introducing solid food textures and developing OFS. Baby-led weaning (BLW) encourages infants to self-feed whole foods. In contrast, traditional spoon-feeding (TSF) and partial baby-led weaning (partial BLW) practices typically involve a parent-led approach that begins with purees. Despite being largely preventable, choking episodes persist in causing parental distress and morbidity globally. Aim: The aim of this thesis was to describe the oral feeding skills of 7 to 10 month old New Zealand infants and their associations with early life factors and feeding behaviours. Additionally, this thesis examined food-related choking in this population. Methods: For this cross-sectional study, infants aged 7 to 10 months and their primary caregivers were recruited from two cities in Aotearoa, New Zealand (Tāmaki Makaurau/Auckland, North Island and Ōtepoti/Dunedin, South Island). Oral feeding skills (OFS) were described using the Child Oral and Motor Proficiency Scale (ChOMPS), concerns with OFS identified, and associations with sociodemographic characteristics and early feeding practices explored. Feeding behaviours were described using the Pediatric Eating Assessment Tool (Pedi-EAT), concerns about problematic feeding behaviours were identified, and their associations with sociodemographic characteristics and early feeding practices were explored. Both tools are patient-reported outcome measures. Within the study population, the prevalence of FRC and the number of FRC episodes were calculated, and implicated foods characterised. Comparisons of FRC episodes were conducted between parent-led complementary feeding practices (TSF and partial BLW) and BLW approaches. Additionally, weighted estimated prevalence was applied using the data from the study population and weighting for the distribution of ethnicity and area-level deprivation. Results: The analysis included 625 eligible infant-parent dyads. Most infants 96% (n = 527) were classified with typical OFS based on their Total Score from the ChOMPS tool. Older infants (9 to < 10 months) were more likely to be associated with “concern” on the ChOMPS compared to the younger infants (7 to < 8 and 8 to < 9 months) (p < .001). Infants born to primiparous mothers were associated with “no concern” compared to those born to multiparous mothers (p = .019). Based on the Pedi-EAT normative reference values, 83% of participants (n = 463) were classified as having no problematic feeding behaviours. Infants born to primiparous mothers were more likely to be associated with "concern" on the Pedi-EAT (p = .009). Of the 625 infants, (n = 120, 19.2%) were reported to have experienced FRC. Among the 108 serious FRC episodes analysed, 45.5% involved whole foods (n = 49) consumed during self-feeding, occurring in 62% of events (n = 67), with the highest frequency (n = 46, 42.6%) in infants aged 8 to < 9 months. Fruits represented 24.3% of FRC episodes (n = 26) and vegetables 20.6% (n = 22), making them the most frequently implicated food categories. Infants aged 7 to < 8 months following a BLW complementary feeding practice demonstrated significantly higher rates of FRC compared to same-age peers using a TSF approach (90% versus 44.4%), (p = .015) when self-feeding. When weighted for national proportions of ethnicity and area-level deprivation, the estimated prevalence of FRC was 18.2% (95% CI [15.3, 21.5]). Conclusions: This study offers new insights into OFS development and feeding behaviours during the second half of infancy, establishing baseline data for healthy developmental variation, and identifying factors that may serve as early indicators of feeding difficulties. This is the first study, to our knowledge, to describe OFS and feeding behaviours in a New Zealand infant study population using validated patient-reported outcome measures. Identifying OFS and problematic feeding behaviours within the study population, with increasing age and primiparity emerging as associated risk factors, provides valuable information for early recognition of feeding development concerns during complementary feeding. Whole fruits and vegetables were the most commonly involved foods in FRC episodes, and BLW practices were significantly associated with FRC risk among the youngest infants. This suggests that parents may require clearer guidance on how to safely introduce whole foods in age-appropriate forms for infants. Additionally, guidelines may benefit from more explicit instruction on transitioning from modified textures to whole foods as infants develop appropriate OFS. These findings highlight an important tension in infant feeding: the foods parents are most likely to select as nutritious choices (fruits and vegetables) present the highest choking risk during complementary feeding.