A new study was released earlier this week, indicating that babies conceived within a year of their older sibling’s birth are at an increased risk of developing autism. The study looked at 662,730 pregnancies, paying close attention to babies conceived less than a year after the mother gave birth to another child. 3,137 of the second-born children had received a diagnosis of autism by the time they were 6 years old. 2,747 of those cases had birthdays less than 36 months after their older sibling.
This study adds another piece to our understanding of the complex causes for autism and fits with the current data suggesting that multiple subtle factors in the environment, particularly the prenatal environment, interact with genetics to impact a child’s developmental outcome.
The strengths of this study include the large sample size and sophisticated statistics to control for factors known to be associated with increased risk of autism. The influence of year of birth on diagnosis (children born earlier in the sample would be more likely to get diagnosed due to longer time passage) was also of interest.
However, the causes of autism are very complex and continued research will be needed to understand exactly how shorter times between pregnancies might increase the risk of autism. As of right now I don’t know that we should take this study as saying you must wait or you’ll be doing harm to your child.
In other autism news, Thrive recently reported on the British Medical Journal’s most recent publication, which further discredits the
research of Dr. Andrew Wakefield, an English doctor whose work attempts to link autism to vaccinations for measles, mumps and rubella. Though exposed as factually incorrect, and possibly even deliberately falsified, Wakefield’s theory has led to thousands of parents questioning the safety of vaccination.
In response, Claire McCarthy, MD, a pediatrician and mother raising five children, wrote a Thrive post that addresses how the abundance of medical misinformation concerning autism and vaccinations has lead to problems for both parents and the medical community.