Objective To assess long term neurodevelopmental outcomes of children born at different gestational ages, particularly 32-33 weeks (moderately preterm) and 34-36 weeks (late preterm), compared with 39-40 weeks (full term). Design Nationwide cohort study. Setting Sweden. Participants 1 281 690 liveborn singleton children without congenital malformations born at 32+0 to 41+6 weeks between 1998 and 2012. Main outcome measures The primary outcomes of interest were motor, cognitive, epileptic, hearing, and visual impairments and a composite of any neurodevelopmental impairment, diagnosed up to age 16 years. Hazard ratios and 95% confidence intervals were estimated using Cox regression adjusted for parental and infant characteristics in the study population and in the subset of full siblings. Risk differences were also estimated to assess the absolute risk of neurodevelopmental impairment. Results During a median follow-up of 13.1 years (interquartile range 9.5-15.9 years), 75 311 (47.8 per 10 000 person years) liveborn singleton infants without congenital malformations had at least one diagnosis of any neurodevelopmental impairment: 5899 (3.6 per 10 000 person years) had motor impairment, 27 371 (17.0 per 10 000 person years) cognitive impairment, 11 870 (7.3 per 10 000 person years) epileptic impairment, 19 700 (12.2 per 10 000 person years) visual impairment, and 20 393 (12.6 per 10 000 person years) hearing impairment. Children born moderately or late preterm, compared with those born full term, showed higher risks for any impairment (hazard ratio 1.73 (95% confidence interval 1.60 to 1.87) and 1.30 (1.26 to 1.35); risk difference 4.75% (95% confidence interval 3.88% to 5.60%) and 2.03% (1.75% to 2.35%), respectively) as well as motor, cognitive, epileptic, visual, and hearing impairments. Risks for neurodevelopmental impairments appeared highest from 32 weeks (the earliest gestational age), gradually declined until 41 weeks, and were also higher at 37-38 weeks (early term) compared with 39-40 weeks. In the sibling comparison analysis (n=349 108), most associations remained stable except for gestational age and epileptic and hearing impairments, where no association was observed; for children born early term the risk was only higher for cognitive impairment compared with those born full term. Conclusions The findings of this study suggest that children born moderately or late preterm have higher risks of adverse neurodevelopmental outcomes. The risks should not be underestimated as these children comprise the largest proportion of children born preterm. The findings may help professionals and families achieve a better risk assessment and follow-up. No additional data available.

中文翻译：

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中度或晚期早产儿的神经发育：国家队列研究

目的 评估不同胎龄出生的儿童的长期神经发育结局，特别是与 39-40 周（足月）相比，32-33 周（中度早产）和 34-36 周（晚期早产）出生的儿童。设计全国队列研究。设置瑞典。参与者 1 281 690 名 1998 年至 2012 年间出生的 32+0 至 41+6 周无先天畸形的活产单胎儿童。 主要结果指标 感兴趣的主要结果是运动、认知、癫痫、听力和视力障碍以及任何综合障碍神经发育障碍，诊断年龄为 16 岁以下。使用根据研究人群和全兄弟姐妹子集中的父母和婴儿特征进行调整的 Cox 回归来估计风险比和 95% 置信区间。还估计了风险差异，以评估神经发育障碍的绝对风险。结果 在中位随访 13.1 年（四分位距 9.5-15.9 年）期间，75 311 名（每 10 000 人年 47.8 名）无先天畸形的活产单胎婴儿至少有 1 次诊断出任何神经发育障碍：5 899 名（每 10 人年 3.6 名） 000 人年）有运动障碍，27 371 人（每 10 000 人年 17.0 人）有认知障碍，11 870 人（每 10 000 人年 7.3 人）有癫痫障碍，19 700 人（每 10 000 人年 12.2 人）视力障碍，以及 20 393 人（每 10 000 人年 12.6 人）听力障碍。与足月出生的儿童相比，中度或晚期早产儿出现任何损伤的风险更高（风险比 1.73（95% 置信区间 1.60 至 1.87）和 1.30（1.26 至 1.35）；风险差异 4.75%（95% 置信区间分别为 3.88% 至 5.60%）和 2.03%（1.75% 至 2.35%））以及运动、认知、癫痫、视觉和听力障碍。神经发育障碍的风险从 32 周（最早胎龄）开始最高，直到 41 周逐渐下降，并且与 39-40 周相比，37-38 周（早期）的风险也更高。在兄弟姐妹比较分析中（n=349 108），除了胎龄、癫痫和听力障碍没有观察到关联之外，大多数关联保持稳定；与足月出生的儿童相比，早产儿发生认知障碍的风险更高。结论 这项研究的结果表明，中度或晚期早产儿出现不良神经发育结果的风险较高。不应低估风险，因为这些儿童占早产儿的比例最大。研究结果可能有助于专业人士和家庭实现更好的风险评估和后续行动。没有其他可用数据。