Work

Timing of tummy-time introduction and developmental outcomes during the first year of life: an exploratory pilot study

Year: 2026

Type: article

Abstract: Prior research has associated greater tummy-time exposure with infant development but less is known about whether the timing of initial tummy-time introduction is related to developmental outcomes. This exploratory longitudinal pilot study examined developmental patterns among 58 infants introduced to tummy time within the first 2 postnatal weeks, after the first 2 postnatal weeks, or not at all. Caregivers reported tummy-time introduction and monthly positioning and behavioral experiences. Development was assessed using the Ages and Stages Questionnaire, Third Edition (ASQ-3) at 3, 6, 9, and 12 months. Complete 5-domain ASQ-3 data were available for 32 infants at 3, 6, and 9 months and 30 infants at 12 months. Kruskal–Wallis tests compared the 3 exposure groups across 5 developmental domains and 4 assessment ages. Rank-based eta-squared effect sizes with 95% bootstrap confidence intervals (CIs) were reported, with Benjamini-Hochberg correction across 20 primary comparisons. Three comparisons had unadjusted p -values .05, but none remained statistically significant after correction. The largest observed effect was for communication at 9 months ( η 2 H =0.275; 95% CI, 0.100–0.507), although CIs were generally wide. Substantial attrition, small and unequal groups, caregiver-reported exposure and outcomes, and potential residual confounding limited the ability to make inferences. These findings do not provide clear evidence of reproducible developmental differences according to the timing of tummy-time introduction. Larger prospective studies should evaluate timing alongside cumulative tummy-time exposure and broader developmental influences.

Source: Frontiers in Pediatrics

DOI: 10.3389/fped.2026.1923077