Supplementary Material for: Fetal and Postnatal Head Circumference Growth: Synergetic Factors for Neurodevelopmental Outcome at 2 Years of Age for Preterm Infants

<i>Abstract:</i> Preterm infants present higher risk of non-optimal neurodevelopmental outcome. Fetal and postnatal growth, in particular head circumference (HC), is associated with neurodevelopmental outcome. <i>Objectives:</i> We aimed to calculate the relationship between HC at birth, HC delta Z-score (between birth and hospital discharge), and non-optimal neurodevelopmental outcome at 2 years of corrected age in preterm infants. <i>Methods:</i> Surviving infants born ≤34 weeks of gestation were included in the analysis. The relationship between the risk of being non-optimal at 2 years and both HC at birth and HC growth was assessed. The 2 Z-scores were considered first independently and then simultaneously to investigate their effect on the risk of non-optimality using a generalized additive model. <i>Results:</i> A total of 4,046 infants with both HC measures at birth and hospital discharge were included. Infants with small HC at birth (Z-score 2) while adjusting for gestational age, twin status, sex, and socioeconomic information. <i>Conclusions:</i> HC at birth and HC dZ-score between birth and hospital discharge are synergistically associated to neurodevelopmental outcome at 2 years of corrected age, in a population-based prospective cohort of preterm infants born ≤34 weeks of gestation.

<i>摘要：</i>早产儿出现不良神经发育结局的风险更高。胎儿期与出生后生长状况，尤其是头围（head circumference, HC），与神经发育结局存在显著关联。
<i>目标：</i>本研究旨在探讨胎龄≤34周早产儿的出生时头围、出生至出院期间的头围变化Z值（HC delta Z-score）与校正胎龄2岁时的不良神经发育结局之间的关联。
<i>方法：</i>本研究纳入胎龄≤34周的存活早产儿开展分析。评估校正胎龄2岁时出现不良神经发育结局的风险，与出生时头围及头围生长情况之间的相关性。本研究先分别分析上述两项Z评分的独立影响，再将二者同时纳入模型，采用广义加性模型（generalized additive model）探究其对不良结局风险的联合作用。
<i>结果：</i>最终共纳入4046名同时具备出生时及出院时头围测量数据的早产儿。在校正胎龄、双胎妊娠状态、性别及社会经济信息后，出生时头围较小（Z评分为2）的婴儿。
<i>结论：</i>在一项纳入胎龄≤34周早产儿的基于人群的前瞻性队列研究中，出生时头围及出生至出院期间的头围变化Z值与校正胎龄2岁时的神经发育结局存在协同关联。