61 - Predictive Value of Persistent Neonatal Arching for Delayed Motor Development: A Prospective Study in the NICU

Publication Number: 1054.61

Tomohiro Mori, Nagoya University Hospital, Nagoya, Aichi, Japan; Yuki Fugane, Nagoya University Hospital, nagoya, Aichi, Japan; Yuya Shirai, Nagoya University Hospital, Nagoya, Aichi, Japan; Kikuko Nishikawa, Kikuko Nishikawa, Occupational Therapist, Nagoya University Hospital, Nagoya, Aichi, Japan; Chiaki Terai, -, Nagoya, Aichi, Japan; Yasuyuki Matsui, Nagoya University Hospital, Nagoya, Aichi, Japan; Yusuke Aoyama, Nagoya University Hospital, Nagoya, Aichi, Japan; Yoshiaki Sato, Nagoya University Hospital, Nagoya, Aichi, Japan

Background: Neck and trunk hyperextension (arching) is often observed among preterm and extremely low birth weight infants in the NICU. It may reflect autonomic or tone dysfunction and is interpreted as discomfort. However, its developmental impact is unclear. Although early care is emphasized, objective bedside indicators for early risk detection remain limited. Clarifying links between postural signs during the NICU stay and later motor outcomes is essential.

Objective: To examine the association between arching duration during the NICU stay and timing of motor milestone attainment (head control, rolling, sitting, crawling, walking) up to 18 months of corrected age, and to determine a cutoff predictive of delay.

Design/Methods: This prospective cohort study (Nagoya University Ethics No. 2022-0037) enrolled 60 neonates admitted between June 2022 and January 2024 who showed arching during physical therapy; 40 completed the follow-up. Weekly observations were conducted in lateral position during wakeful states for at least one minute. Arching was defined as ≥30° between the acromion-greater trochanter and the external auditory meatus-parietal lines. Duration was measured from onset to resolution. Milestones were assessed at 6, 12, and 18 months corrected age. Potential confounders included birth weight, gestational age, Apgar score, ventilation days, surgery, and infection. Analyses included Spearman correlation, t-tests, GLM (ANCOVA), and ROC (p < 0.05).

Results: Inter-rater reliability was high (Fleiss' κ = 0.883). Median arching duration was 77 days (range 0-294; mean 90.4 ± 91.4). Mean birth weight and gestational age were 2239.7 ± 953 g and 34.6 ± 4.4 weeks (Table). Longer arching correlated with delayed milestones (p < 0.01): head control (r = 0.42), rolling (r = 0.44), sitting (r = 0.45), crawling (r = 0.43), and walking (r = 0.50). Infants with surgery had longer arching (134.5 vs. 71.5 days, p = 0.044), and duration correlated with ventilation days (r = 0.33, p = 0.036). GLM confirmed arching duration as an independent predictor of delay. ROC identified 143 days as the optimal cutoff for delayed walking (>2 SD): AUC = 0.745, sensitivity = 52.9%, and specificity = 91.3% (Figure). About half of infants exceeding 143 days showed delay, indicating high specificity for identifying those at risk.

Conclusion(s): Persistent arching during the NICU stay predicts delayed motor acquisition. Duration beyond 143 days is a useful cutoff for high-risk screening. As arching is easily observed, it serves as a practical early marker. Further studies are needed to confirm these findings.

ROC Curve for Arching Duration (Cutoff = 143 days).
Receiver operating characteristic (ROC) analysis for predicting delayed independent walking (>2 SD below mean at 18 months corrected age)._x000B_The optimal cutoff value of arching duration was 143 days, yielding an AUC of 0.745 (95% CI 0.44-0.53, p = 0.0023), with sensitivity 52.9% and specificity 91.3%, indicating clinically meaningful discrimination.

Clinical characteristics of the study population (n=40).
Values are presented as median (interquartile range, IQR) or percentage where appropriate.
*Gestational age was converted from days (25th = 218, 50th = 254, 75th = 267.5) to weeks (31.1, 36.3, and 38.2 weeks, respectively) for presentation.