Relationships between multiple births and autism spectrum disorders, cerebral palsy, and intellectual disabilities: autism and developmental disabilities monitoring (ADDM) network-2002 surveillance year.
Twins and triplets are not more likely to have autism, but they do face higher cerebral palsy risk.
01Research in Context
What this study did
Kim and colleagues looked at birth records from 1994 and matched them to autism, cerebral palsy, and intellectual disability cases found in 2002.
They used the ADDM Network, a tracking system that pulls data from schools, clinics, and health departments across several U.S. states.
What they found
Twins and triplets were no more likely to have autism than single-born kids.
Multiple births did show a strong link to cerebral palsy, and a weaker, non-significant link to intellectual disability.
How this fits with other research
Lung et al. (2018) also found no autism rise in kids born through assisted reproductive technology, a group that often has more twins. This backs the null autism result.
Sievers et al. (2020) found that being born early, not being a twin, raised autism odds 3.5 times in Brazil. The studies differ because prematurity and multiple births are separate risk paths.
Weiss et al. (2001) saw no link between mild birth problems and autism severity in kids with tuberous sclerosis. Their null fits here, but their sample had a known genetic cause, so birth events mattered less.
Why it matters
When parents of twins ask if their kids face higher autism risk, you can say the data show no extra risk from the twin status itself. Keep watching for cerebral palsy signs instead, and use the same screening tools you use for all children.
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02At a glance
03Original abstract
Since the 1970s, the prevalence of multiple births (MBs) in the United States has increased significantly. This has been attributed, in large part, to iatrogenic MBs resulting from infertility treatments that include ovulation stimulation. A past study has indicated that children from MBs have an increased prevalence of cerebral palsy (CP). Other studies also have suggested an association between MBs and intellectual disabilities (ID) and autism spectrum disorders (ASDs); however, results have been inconsistent. From the Autism and Developmental Disabilities Monitoring (ADDM) Network, a surveillance project among several US populations, we obtained MB estimates among children born in 1994 and classified by 8 years of age as having: an ASD (n=1,626 total children from 11 sites; 50 born as part of an MB); CP (n=302 total children from 3 sites; 25 born as part of an MB); or ID (n=1,195 total children from 3 sites; 45 born as part of an MB). All three MB estimates were notably higher than age-adjusted expected estimates of naturally conceived MBs derived from 1971 US natality data. However, when MB estimates from the ADDM Network were compared with expected MB estimates derived from 1994 natality data for the states corresponding to the relevant ADDM Network sites, we observed no association with ASDs (observed/expected=1.08 [0.78-1.38]), a moderate, but not statistically significant association with ID (observed/expected=1.34 [0.95-1.73]), and a strong association with CP (observed/expected=2.96 [1.80-4.12]). Further investigation of specific types of MBs (natural vs. iatrogenic) is warranted.
Autism research : official journal of the International Society for Autism Research, 2008 · doi:10.1002/aur.41