英国伦敦帝国理工学院Anders Husby团队研究了出生胎龄与青少年认知结果的相关性。2023年1月18日出版的《英国医学杂志》发表了这项最新研究成果。

为了探讨出生时孕龄与青春期认知结局的关系，研究组进行了一项基于全国人口的全同胞队列研究。选择丹麦1986年1月1日至2003年12月31日期间出生的120万儿童，其中792724名有一个或多个同期出生的兄弟姐妹。

在义务教育结束时（九年级，15-16岁），双盲评估员对书面语言（丹麦语）和数学考试的分数进行评分，此外，还对嵌套的男性青少年子队列进行了征兵时的智力测试分数（主要是18岁）。学校成绩根据考试年份标准化为z分数，智力测试分数根据出生年份标准化成z分数。

在792724名全同胞的队列中中，44322名（5.6%）出生于怀孕37+0周之前。在校正了多个混杂因素（性别、出生体重、畸形、父母出生时的年龄、父母的教育水平和兄弟姐妹的数量）和兄弟姐妹之间的共同家庭因素后，与40孕周出生的儿童相比，只有小于34孕周出生的儿童在书面语言（≤27孕周的z评分差−0.10）和数学（32-33孕周的z评分差−0.05，28-31孕周的z评分差−0.13，≤27孕周的z评分差−0.23）z分数方面明显降低。

在一个智力测试分数为全兄弟的嵌套子队列中，与40孕周出生的儿童相比，出生于32-33、28-31和≤27孕周的孩子智商下降分别为2.4、3.8和4.2分，而出生于34-39孕周的儿童智商下降<1分。

研究结果表明，怀孕34-39周出生的孩子和孕40周出生的孩子在青春期的认知结果方面没有差异，而孕龄<34周的孩子在多个认知领域表现出明显的缺陷。

附：英文原文

Title: Gestational age at birth and cognitive outcomes in adolescence: population based full sibling cohort study

Author: Anders Husby, Jan Wohlfahrt, Mads Melbye

Issue&Volume: 2023/01/18

Abstract:

Objective To investigate the association between gestational age at birth and cognitive outcomes in adolescence.

Design Nationwide population based full sibling cohort study.

Setting Denmark.

Participants 1.2 million children born between 1 January 1986 and 31 December 2003, of whom 792724 had one or more full siblings born in the same period.

Main outcome measures Scores in written language (Danish) and mathematics examinations as graded by masked assessors at the end of compulsory schooling (ninth grade, ages 15-16 years), in addition to intelligence test score at military conscription (predominantly at age 18 years) for a nested sub-cohort of male adolescents. School grades were standardised as z scores according to year of examination, and intelligence test scores were standardised as z scores according to year of birth.

Results Among 792724 full siblings in the cohort, 44322 (5.6%) were born before 37+0 weeks of gestation. After adjusting for multiple confounders (sex, birth weight, malformations, parental age at birth, parental educational level, and number of older siblings) and shared family factors between siblings, only children born at <34 gestational weeks showed reduced mean grades in written language (z score difference 0.10 (95% confidence interval 0.20 to 0.01) for ≤27 gestational weeks) and mathematics (0.05 (0.08 to 0.01) for 32-33 gestational weeks, 0.13 (0.17 to 0.09) for 28-31 gestational weeks, and 0.23 (0.32 to 0.15) for ≤27 gestational weeks), compared with children born at 40 gestational weeks. In a nested sub-cohort of full brothers with intelligence test scores, those born at 32-33, 28-31, and ≤27 gestational weeks showed a reduction in IQ points of 2.4 (95% confidence interval 1.1 to 3.6), 3.8 (2.3 to 5.3), and 4.2 (0.8 to 7.5), respectively, whereas children born at 34-39 gestational weeks showed a reduction in intelligence of <1 IQ point, compared with children born at 40 gestational weeks.

Conclusions Cognitive outcomes in adolescence did not differ between those born at 34-39 gestational weeks and those born at 40 gestational weeks, whereas those with a gestational age of <34 weeks showed substantial deficits in multiple cognitive domains.

DOI: 10.1136/bmj-2022-072779

Source: https://www.bmj.com/content/380/bmj-2022-072779