Study Confirms Link between Older Maternal Age and Autism，Maternal age and autism are both on the rise--but only a small fraction of the increasing incidence can be explained by the trend toward later childbearing
The researchers found that mothers over 40 had a 51 percent higher risk of having a child with autism than mothers 25 to 29, and a 77 percent higher risk than mothers under 25. Autism—a developmental disorder characterized by impaired social interaction and communication—appears to be on the rise.
Parental age over 40 years was consistently found to be associated with an increased risk of autism. As Figure 2 shows, prevalence rates for autism when parental age exceeded 40 years were higher than the prevalence in the general population. Among all children born between 1992 and 2000, regardless of parental age, the prevalence of autism was 34 per 10 000. In contrast, the prevalence rate for children born to parents over 40 years of age was 56 per 10 000. Prevalence rates were slightly higher when maternal age exceeded 40 years relative to when paternal age exceeded 40 years. However, there were significantly more men over 40 years of age, with and without children with autism, in our population.
亲眼见过很多孩子大脑神经系统方面的问题，比如自闭症，阿斯伯格综合症，语言表达能力明显差，情绪控制能力弱，……，等等，另外还有孩子婴儿期就出现的严重湿疹和过敏。原因当然很多很复杂，但也发现那些问题孩子的母亲, 怀孕生育的年龄一般偏大（>30）, 而且怀孕时的脑力工作强度高+压力大+工作时间长。怀疑母亲的内分泌系统在高龄高压状况下失去平衡，某些激素水平过高/过低，影响胎儿脑部神经发育。而且很多例子提示，工作强度/压力/时间比生育年龄对孩子大脑的影响更大。
此猜测是否正确未知。觉得妇女生育年龄低一些，工作压力小一些，对母子，尤其是孩子，有好处。
这是自然界的规律。现代不少人对钱太着迷了，把最佳的青春用来追求什么学业事业，等钱够了再来生育，晚了！
男女是一个Team,男的因该主外，努力赚钱，女的应该在青春期间安心生育，给孩子最好的一切。怀孕9个月，哺乳至少一年（才能给孩子们最好的大脑和身体），而且主流家庭需要生育至少3个孩子，一个社会才能持续稳定。这就需要女性在20-30之间全心放在生育方面。事业可以在孩子大了以后开始。那些需要吃青春饭的行业，让其他人去拼吧。她们错过生育年龄，她们生育减少或者没有，等于是把她们基因的未来腾出来给我们的后代。
这么年轻生娃，让小两口怎么搞，生活节奏形态都整天围着孩子团团转，啥事都别干了？ 生活目的不是简单仅为繁衍，女性也要地位，工作生活，经济独立，更不能全依赖男的，再说这年纪自己还是个孩子呢，连很好照顾自己都成问题，没知识没能力 怎能很好担起家庭，抚养培育下一代的责任？ 养娃又不是养个小猫小狗，给吃穿不饿着那么简单，这样会带来诸多社会问题。既然生娃就要会养，父母就要好好负起责任，培养出身心健康的孩子，不仅为自己也要为社会尽责，重质量不要数量，否则还不如不要。
我家族亲戚里从上上辈子就没早婚早育的，生孩子最早起码30+，也没见各个脑子智力出问题啊。
不是必然。比如抽烟/肺癌；3. 基于大龄生的孩子没问题的有限案例，不能排除从概率角度，低龄生的孩子更健康。大龄生的孩子大部分是都正常，但低龄生的孩子可能正常比例更高。
孩子有自闭症的问题，40岁以上产妇，与25-29年龄段产妇相比，风险增加51%；与25岁以下产妇相比，风险增加77%。据此换算，如果40岁以上产妇孩子有自闭症的风险为100，那么：
产妇年龄段 相对风险
<25 56.5
25-29 66.2
>40 100
另外，有文献指出，高龄产妇生下的女孩，偏男性化。
信息来源：
Study Confirms Link between Older Maternal Age and Autism，Maternal age and autism are both on the rise--but only a small fraction of the increasing incidence can be explained by the trend toward later childbearing
https://www.scientificamerican.com/article/autism-maternal-age/
The researchers found that mothers over 40 had a 51 percent higher risk of having a child with autism than mothers 25 to 29, and a 77 percent higher risk than mothers under 25. Autism—a developmental disorder characterized by impaired social interaction and communication—appears to be on the rise.
如果第一个孩子是在二十多岁生的，第二个孩子在30岁以后生，和30岁以后初产有区别吗？
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2724463/
Association of Parental Age and Autism Over TimeParental age over 40 years was consistently found to be associated with an increased risk of autism. As Figure 2 shows, prevalence rates for autism when parental age exceeded 40 years were higher than the prevalence in the general population. Among all children born between 1992 and 2000, regardless of parental age, the prevalence of autism was 34 per 10 000. In contrast, the prevalence rate for children born to parents over 40 years of age was 56 per 10 000. Prevalence rates were slightly higher when maternal age exceeded 40 years relative to when paternal age exceeded 40 years. However, there were significantly more men over 40 years of age, with and without children with autism, in our population.
统计在1992年至2000年之间出生的所有儿童中，无论父母年龄如何，自闭症的患病率为每10 000例中有34人。相比之下，40岁以上父母所生的孩子的患病率为每10 000例中有56例。
请回去查查：normalization . 如果你明白了 normalization 的意思，问题就解决了。
美国的一些低端人口，十几岁就怀孕生孩子，孩子生下来很多都是一堆问题。