Cross-Sectional study on cranial shape measurement values of 2,165 preterm infants in Beijing

Background The incidence rate of postural cranial abnormality is high. They often accompany facial asymmetry, affecting the appearance and potentially even the development of the nervous system in affected children. To investigate the epidemiological characteristics of the detection rate of postural cranial abnormality in preterm infants, providing a basis for early diagnosis and intervention timing. Methods A retrospective study was conducted on cranial measurement data from 2,165 preterm infants who visited the Child Health Care Center of Peking University Third Hospital for the first time between January 1, 2022, and April 30, 2025. Collect basic information of premature infants. Cranial shape data, including Cranial Vault Asymmetry, Cranial Vault Asymmetry Index and Cephalic Ratio, were acquired using the STARscanner 2.0 laser data acquisition system. Preterm infants were divided into three groups based on corrected age: 0–2 months group, 3–4 months group, and 5–6 months group. Results This study analyzed 2,165 infants and detected postural cranial abnormality in 1,420 cases. Grouped by corrected age, the postural cranial abnormality was highest in the 0–2 month group (81.2%, 371/457), followed by the 5–6 month group (74.2%, 495/667), and lowest in the 3–4 month group (53.2%, 552/1,041). Upon subdivision of deformation types, it was observed that the detection rate of plagiocephaly fluctuated in a “V” shape among the 0–2, 3–4, and 5–6 month groups (42.2% vs 33.3% vs 37.3%); the detection rate of brachycephaly significantly increased with age (12.7% vs 9.0% vs 19.8%); asymmetric brachycephaly showed no significant change between the 0–2 month and 5–6 month groups (8.8% vs 8.5%); and the detection rate of scaphocephaly significantly decreased between the 0–2 month and 5–6 month groups (17.5% vs 8.5%). Conclusion The incidence of postural cranial abnormality is high among Chinese preterm infants, with plagiocephaly being the predominant type. The prevalence of cranial abnormalities shows a U-shaped trend with increasing corrected age (first decreasing then increasing), indicating the necessity for early and continuous intervention. This study provides evidence for incorporating cranial shape screening into routine follow-up for preterm infants and advancing the intervention window to the corrected age of 0–2 months.