产妇感染与婴儿脑瘫风险增加相关

温哥华——加利福尼亚大学（旧金山）的Joshua Bear博士在2014年儿科学会联合会年会上公布 了一项根据加利福尼亚州600万例出生记录进行的分析，研究结果显示妊娠妇女孕期羊水内外感染与胎儿出现脑瘫的风险增高相关。

研究者发现，被诊断为绒毛膜羊膜炎的住院产妇所生育的孩子发生脑瘫的风险增加4倍，泌尿生殖系统和呼吸系统感染患者出现脑瘫的风险增加2倍。

斯坦福（加利福尼亚州）大学儿科副教授兼该校政策、结果和预防中心主任的Lee M. Sanders博士认为“这是一项非常重要的研究，它让我们在探究脑瘫成因的路上前进了一步，”。

Bear博士及其合作者分析了1991年至2001年间加州的出生记录，以及自2006年来接受加州开发服务部门提供的脑瘫治疗的所有患儿记录。共查找到近8500例脑瘫患儿记录，即每1000个出生活婴中有1.4例脑瘫患儿。

对感染诊断的分析发现，6%产妇未受到感染因素的影响，15.3%的产妇的婴儿被诊断为脑瘫，相对风险2.7。在后者的患者中，有7.6%为绒毛膜羊膜炎患者，5.2%则伴有其他泌尿生殖系统感染，3.5%伴有呼吸系统感染。

在绒毛膜羊膜炎住院患者中，早产儿脑瘫风险增加4倍，足月儿脑瘫风险则增加2倍。而在其他泌尿生殖系统感染中，临产前才入院的患者分娩出脑瘫患儿的风险增加1.4倍， 而住院治疗的患者分娩出脑瘫患儿的风险则增加1.9倍。呼吸系统感染患者与其相似，风险增加分别为2倍和2.6倍。

其他泌尿生殖系统和呼吸系统感染可导致脑瘫风险增加，即便是在临产前才入院也是一样，Bear博士在发言中阐述到，这些数据均提示这“这些感染可能直接或者间接地导致胎儿大脑发育受损，这些不能简单地认为是另一种分娩并发症，”。

社会人口学危险因素分析显示，18岁以下的年轻女性和年龄超过35岁的女性生育的孩子更易被诊断为脑瘫。与白人和西班牙裔女性相比，黑人妇女生育脑瘫孩子的风险较高，亚洲女性的生育风险则较低。受教育年限与脑瘫风险呈负相关。另外，男婴的脑瘫风险略高于女婴。

在调整产妇年龄、种族、教育程度、社会经济地位和婴儿性别的因素后，感染和脑瘫风险增加之间的关系保持不变。

该研究存在一些局限性，包括ICD-9编码的使用，研究者无法解释的相关住院合并症，以及被限制在医院内为基础的诊断。

Bear博士强调了该研究发现中需要进一步探究的几个方面，包括脑瘫和呼吸系统感染间的关系，以及脑瘫风险是否可以通过预防和治疗感染而得以降低。

Sanders博士还认为这些发现还能够“成为帮助我们进行公共健康干预的依据，如可提高孕妇的流感疫苗接种率“

Bear博士和Sanders博士声明无任何经济利益相关冲突。

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By: NASEEM S. MILLER, Ob.Gyn. News Digital Network

AT THE PAS ANNUAL MEETING

Vitals

Key clinical finding: The association between maternal infections and increased risk of CP could be a call for public health interventions, such as higher rate of flu vaccination for pregnant women.

Major finding: Pregnant women who were hospitalized with diagnosis of chorioamnionitis had a fourfold increase in risk of having a child with cerebral palsy (CP), while genitourinary and respiratory infections increased that risk by twofold, each.

Data source: Analysis of California birth records from 1991 to 2001, and records of all children receiving services for CP from the California Department of Developmental Services through 2006.

Disclosures: Dr. Bear and Dr. Sanders had no relevant disclosures.

VANCOUVER, B.C. – Intra- or extra-amniotic fluid infections during pregnancy are associated with an increased risk of having a child with cerebral palsy, according to analysis of six million California birth records.

Researchers found that pregnant women who were hospitalized with diagnosis of chorioamnionitis had a fourfold increase in risk of having a child with cerebral palsy (CP), while genitourinary and respiratory infections increased that risk by twofold, each.

"I think this is a very important study, and it took us a step further in trying to understand what could cause cerebral palsy," said Dr. Lee M. Sanders, associate professor of pediatrics and codirector of the Center for Policy, Outcomes, and Prevention at Stanford (Calif.) University. But because the study shows an association only, "it’s important not to cause alarm," said Dr. Sanders, who was not involved in the study.

Dr. Joshua Bear of the University of California, San Francisco, and his colleagues analyzed the California birth records from 1991 to 2001, in addition to records of all children receiving services for CP from the California Department of Developmental Services through 2006.

There were close to 8,500 CP cases, or 1.4 per 1,000 live births, which is at the lower end of some of the reported statistics, Dr. Bear said.

Analysis of infection diagnoses showed that 6% of the women had unaffected births, while 15.3% had children with CP, with a relative risk of 2.7. Among the latter group, 7.6% had chorioamnionitis, 5.2% had other genitourinary infections, and 3.5% had respiratory infections.

Among women hospitalized with chorioamnionitis, there was a fourfold increase in risk of having CP in preterm infants and twofold increase in term births. Most women hospitalized with chorioamnionitis gave birth at that hospitalization, said Dr. Bear.

For other genitourinary infections, there was a 1.4-fold increase in the risk of CP for prenatal hospitalization, and 1.9-fold increase for birth hospitalization.

Respiratory infections showed a similar trend, with a twofold increased risk for prenatal hospitalization and 2.6-fold increase risk for birth hospitalization.

Increased risk of CP with other genitourinary and respiratory infections, even during prenatal hospitalization, suggest that "these infections may be directly or indirectly contributing to harm on the developing fetal brain and not be simply another complication during delivery," Dr. Bear said during his presentation at the annual meeting of Pediatric Academic Societies.

Analysis of sociodemographic risk factors showed that women younger than 18 and older than 35 were more likely to have a child with CP. Black women were at a higher risk of CP, compared with white and Hispanic women, and Asian women were at lower risk. Years of education was inversely associated with the risk of CP. Also, male infants were at a slightly higher risk of CP than were their female counterparts.

Yet when researchers adjusted for maternal age, race, education, socioeconomic status, and infant sex, the association between infections and increased risk of CP remained the same.

Dr. Bear and his colleagues also stratified the data by presence of birth asphyxia, to find clues if it could be a cause for CP. The results showed a large drop in rate ratios of chorioamnionitis, from 4 to 1.5 when asphyxia was diagnosed at birth, but the rates for other genitourinary and respiratory infections remained the same. "This suggests that there’s some interaction between chorioamnionitis and presence of birth asphyxia, although the nature of that interaction is unclear." said Dr. Bear.

The study had several limitations, including the use of ICD-9 codes, researchers’ inability to account for comorbid conditions related to hospitalization, and being limited to hospital-based diagnoses.

The findings, said Dr. Bear, highlighted the need for further research in several areas, including the association between CP and respiratory infections, and whether risk of CP can be decreased by preventing or treating the infections.

The findings can also "help us with public health interventions, such as better rates of influenza vaccinations among pregnant women," said Dr. Sanders.

Dr. Bear and Dr. Sanders had no relevant disclosures.