In vitro fertilization (IVF) has helped thousands of seemingly infertile couples become pregnant since it was introduced in the U.S. in 1981. In the past ten years, the number of couples who chose assisted reproductive technology (ART) has doubled, and one percent of all babies born in the U.S. today are the result of in vitro fertilization. With a success rate of 30.5 percent, it’s no wonder IVF is a popular choice for many couples (CDC, 2012).
However, since it was introduced, there has been ongoing concern about whether IVF increases health risks for the baby who’s conceived. Because there are so many possible causes of birth defects—and because some defects surface later in life—it’s hard to isolate the potential risks of IVF.
ADHD and In Vitro Fertilization: Studies from Around the World
Recently, three studies have explored the link between chronic conditions, such as ADHD and IVF.
For a 2009 study at Eastern Virginia Medical School in Norfolk, 173 young adults who were conceived using IVF completed a self-administered questionnaire. More than 33 percent of respondents reported being diagnosed with ADHD (verses 3-5 percent in the general population). Researchers speculated that stress during a high-risk pregnancy or overprotective parenting of children born via IVF may be responsible for the high rates of ADHD in this group (Beydoun, H., et. al., 2010).
Other, potentially related conditions, including binge drinking and increased exercise, were also reported by this group. Clinical depression was also more common (16 percent were diagnosed in the study group verses 13 percent in the greater population). However, this was a very small study and did not examine the rate of ADHD in the parents of study participants. Also, self-reported information is not always accurate (Beydoun, H., et. al., 2010).
In a 2010 study in Sweden, 28,158 children who were conceived using IVF and were prescribed ADHD medication were examined to determine whether a higher percentage of the IVF children were diagnosed with ADHD than were diagnosed in the comparison group of more than 2 million other Swedish children (Källén, A., et. al., 2011).
That study showed only a weak-to-moderate increase in the number of IVF-born children who had ADHD. Interestingly, there was a higher risk for ADHD in girls in the Swedish study as compared to boys in the U.S. study, which could indicate that there is actually no gender difference (Källén, A., et. al., 2011).
Although the Swedish study was larger and included less subjective data, it still may not accurately represent the number of children with ADHD who were born via IVF. Not all children with ADHD were evaluated—only those who were on the medications methylphenidate or atomixetine. These drugs are frequently prescribed for patients with moderate or severe ADHD, but not for those with milder forms of the condition (Källén, A., et. al., 2011).
A third study, conducted in Israel in 2010, showed a significant increase in cases of mild to moderate autism in children conceived using IVF. 10.5 percent of the 461 children studied who were diagnosed with an autism spectrum disorder were conceived using IVF, a significantly higher number than the 3.5 percent autism rate in the general Israeli population (Science Daily, 2012).
The lead researcher in the Israeli study speculates that “imprinting”—the biological procedure that determines which of the parents’ genes will be expressed in the embryo—may be disrupted during IVF. However, further research is needed to determine whether certain genes or genetic processes linked to ADHD are affected by IVF (Science Daily, 2012).
It’s difficult to parse out exactly which risk factors lead to ADHD, autism, cerebral palsy, and other disorders linked to IVF. Mothers who choose IVF tend to be older than those who conceive naturally, and a higher percentage of children born via IVF are born prematurely and with a low birth weight than in the general population. These factors may also increase the risk of chronic conditions, such as ADHD, in IVF children.
Regardless of whether parental, environmental, or genetic factors—or a combination of these— are responsible for ADHD, IVF children with the condition deserve to be identified and appropriately treated. Couples considering IVF as an infertility treatment should also be aware of the potential risks for their future children.