孕妇妊娠期间发热会使儿童患自闭症或发育迟缓的风险增加一倍以上
2012-05-28 12:16:18   来源： 丁香园   作者：  评论：0 点击：

加州大学戴维斯分校的研究者发现，妊娠期间发热的母亲生下的孩子比正常发育的儿童患自闭症或发育迟缓的风险增加一倍以上，服用药物治疗发热可以对抗这种影响。

在 做这个研究的时候，OussenyZerbo还是加州大学戴维斯分校的一名博士生，现在已经是一名加利福尼亚州北部凯萨医疗中心的博士后。Ousseny Zerbo说，我们的研究提供了强有力的证据表明，控制妊娠期间的发热可以有效降低儿童患自闭症或发育迟缓的风险，我们建议孕妇如果患有发热应该服用退热 药，如果发热持续，则应该寻求医疗帮助。这个研究结果在线发表于杂志《自闭症和发育障碍》上。该研究首提这样的观点：无论发热属于何种原因（包括流感在 内），妊娠期间的治疗均会降低儿童患自闭症和发育迟缓的风险。

基因和环境因素导致儿童自闭症(CHARGE)研究是一个大型的病例对照试 验，上面的结果是基于该研究的数据得出的。另外一个基于CHARGE的研究发现，如果母亲肥胖或者患有糖尿病，同样会增加儿童患自闭症的风险。Irva Hertz-Picciotto是加州大学戴维斯分校的一名公共卫生学教授，同时也是CHARGE的主要研究人员。她指出发热主要是由于急性感染导致的， 是一种短期的、自然免疫系统对于感染或者损伤的保护性反应；而慢性炎症不再是有益的，反而可以损伤健康组织，还可能会导致母亲患代谢异常疾病，如糖尿病和 肥胖。因为机体炎症状态会导致发热，同样也会伴随肥胖和糖尿病，自然就能想到这样一个问题：炎症因子是不是在自闭症的发生中发挥作用？她解释说，人体受到 细菌或者病毒感染后，人体就会启动一种愈合反应，刺激白细胞把炎症细胞因子释放到血流中去。一些细胞因子可以穿过胎盘，因而就会到达胎儿的中枢神经系统， 从而潜在的改变神经递质的水平，影响大脑的发育。Hertz-Picciotto说，我们确信需要更多的研究来发现炎症影响大脑发育的机制。

CHARGE 研究中纳入了出生于加利福尼亚州并且生活于该州北部的2到5岁不同种族的儿童。当前研究纳入的儿童中，有538名患有自闭症，163名患有发育迟缓但是没 有自闭症，421名为正常发育，他们的母亲回答了关于以下内容的标准问卷：怀孕期间是否患有流感和/或发热？是否使用药物治疗这些疾病？研究结果显示，妊 娠期间患有流感与儿童患有自闭症或发育迟缓之间没有相关性。与正常发育儿童的母亲相比，患有自闭症儿童的母亲或患有发育迟缓儿童的母亲报告发热的比例明显 要高，这种发热可以是任何原因导致的，相应的倍数分别为2.12倍和2.5倍。对于服用退烧药治疗的母亲的儿童来说，患自闭症的风险和母亲妊娠期间未患发 热的儿童没有差别。

Irva Hertz-Picciotto认为，由于CHARGE研究采用了大样本的人群抽样，同时记录了参与者的详细信息，因此基于该研究数据的结果是值得信赖 的。其他CHARGE研究结果发现，产前和怀孕第一个月服用维生素可以预防儿童自闭症，孕妇居住在高速公路附近或者严重空气污染地区会增加儿童患自闭症的 风险。

Hertz-Picciotto说，CHARGE获得了儿童及其父母的生活环境、人口学和医疗信息，这为进行各种流行病学研究奠定了坚实的基础，这些研究可以帮我们找到保护儿童神经发育的措施。
A team of UC Davis researchers has found that mothers who had fevers during their pregnancies were more than twice as likely to have a child with autism or developmental delay than were mothers of typically developing children, and that taking medication to treat fever countered its effect.

"Our study provides strong evidence that controlling fevers while pregnant may be effective in modifying the risk of having a child with autism or developmental delay," said Ousseny Zerbo, lead author of the study, who was a Ph.D. candidate with UC Davis when the study was conducted and is now a postdoctoral researcher with the Kaiser Permanente Northern California Division of Research. "We recommend that pregnant women who develop fever take anti-pyretic medications and seek medical attention if their fever persists."

Published online in the Journal of Autism and Developmental Disorders, the study is believed to be the first to consider how fever from any cause, including the flu, and its treatment during pregnancy could affect the likelihood of having a child with autism or developmental delay.

The results are based on data from a large, case-control investigation known as the Childhood Autism Risk from Genetics and the Environment (CHARGE) Study. Another recent study based on CHARGE data found that mothers who were obese or diabetic had a higher likelihood of having children with autism.

Irva Hertz-Picciotto, a professor of public health sciences at UC Davis and principal investigator of CHARGE, pointed out that fever is produced by acute inflammation - the short-term, natural immune system reaction to infection or injury - and that chronic inflammation, which no longer serves a beneficial purpose and can damage healthy tissue, may be present in mothers with metabolic abnormalities like diabetes and obesity.

"Since an inflammatory state in the body accompanies obesity and diabetes as well as fever," said Hertz-Picciotto, "the natural question is: Could inflammatory factors play a role in autism?"

She explained that when people are infected by bacteria or viruses, the body generally reacts by mounting a healing response that involves the release of pro-inflammatory cytokines from white blood cells into the bloodstream. Some cytokines are able to cross the placenta, and therefore could reach the fetal central nervous system, potentially altering levels of neurotransmitters and brain development.

"We definitely think more research is necessary to pinpoint the ways that inflammation could alter brain development," said Hertz-Picciotto.

CHARGE includes an ethnically diverse population of children aged 2 to 5 years born in California and living in Northern California. The current study included 538 children with autism, 163 children with developmental delay but not autism, and 421 typically developing children whose mothers answered standardized questionnaires about whether they had the flu and/or fever during pregnancy and if they took medications to treat their illnesses.

The results showed that flu during pregnancy was not associated with greater risks of having a child with autism or developmental delay. Fever from any cause during pregnancy, however, was far more likely to be reported by mothers of children with autism (2.12 times higher odds) or developmental delay (2.5 times higher odds), as compared with mothers of children who were developing typically. For children of mothers who took anti-fever medication, the risk of autism was not different from the risk in children whose mothers reported no fever.

According to Irva Hertz-Picciotto, results based on CHARGE data are noteworthy because of the study's large population-based sample and detailed information on participants. Other CHARGE evaluations have found that taking prenatal vitamins prior to and during the first month of pregnancy may help prevent autism and that living near a freeway or in areas with high regional air pollution is associated with higher risk of autism in children.

"CHARGE has obtained a wealth of environmental, demographic and medical information on young children and their parents and provides a solid basis for a variety of epidemiologic studies," said Hertz-Picciotto. "Those studies are helping us find ways to protect childhood neurodevelopment."