Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY.
Paediatr Perinat Epidemiol. 2014 Jan;28(1):58-66. doi: 10.1111/ppe.12094. Epub 2013 Nov 8.
Associations between maternal parity and outcomes in offspring may provide evidence for involvement of prenatal exposures. The objective of this study was to determine whether risk for autism spectrum disorders (ASD) is associated with maternal parity.
Diagnoses of childhood autism, Asperger syndrome, and pervasive developmental disorder, not otherwise specified (PDD-NOS) were examined separately and as a group. The study was conducted in the Finnish Prenatal Study of Autism, which is based in a national birth cohort. Children born in Finland in 1987-2005 and diagnosed with ASD by 2007 were identified through the Finnish Hospital Discharge Register. Four matched controls were selected for each case using the Finnish Medical Birth Register. The association between parity and each ASD was determined using conditional logistic regression and adjusted for number of children in the sibship and other potential confounders.
ASDs combined showed a pattern of decreasing risk with increasing parity (odds ratio OR for fourth or greater vs. first-born children, 0.43 [95% confidence interval (CI): 0.35, 0.51]). For childhood autism, an adjusted OR of 1.51 [95% CI 1.27, 1.81] was observed for second vs. first-born children. Associations for Asperger syndrome and PDD-NOS were consistent with those for all ASDs.
Differences in patterns of association between maternal parity and ASD subtypes may indicate varying contributions of specific environmental factors to risk; however, differences in diagnosis or in treatment seeking for childhood behavioural problems cannot be ruled out, particularly for higher functioning cases.
母婴生育次数与后代结局之间的关联可能为产前暴露的作用提供证据。本研究旨在确定自闭症谱系障碍（ASD）的风险是否与母婴生育次数有关。
分别和作为一个整体，对儿童自闭症、阿斯伯格综合征和广泛性发育障碍未特定型（PDD-NOS）的诊断进行了研究。该研究是在芬兰自闭症产前研究中进行的，该研究基于全国性的出生队列。通过芬兰住院病人登记处，确定了芬兰 1987 年至 2005 年出生、并在 2007 年之前被诊断为 ASD 的儿童。使用芬兰出生登记处为每个病例选择了四个匹配对照。使用条件逻辑回归确定了生育次数与每种 ASD 之间的关联，并根据同胞子女数量和其他潜在混杂因素进行了调整。
ASD 综合结果显示，随着生育次数的增加，风险呈下降趋势（第四胎及以上与第一胎儿童相比的比值比[OR]为 0.43[95%置信区间（CI）：0.35，0.51]）。对于儿童自闭症，与第一胎相比，第二胎的调整 OR 为 1.51[95%CI 1.27，1.81]。阿斯伯格综合征和 PDD-NOS 的关联与所有 ASD 的关联一致。
母婴生育次数与 ASD 亚型之间关联模式的差异可能表明特定环境因素对风险的不同贡献；然而，不能排除儿童行为问题诊断或寻求治疗方面的差异，尤其是对功能较高的病例。
