Assisted reproductive technology (ART) has helped many parents with fertility issues conceive and have children. ART is involved in nearly 8% of European births and more than 5% of children born in the U.S. Previous studies have proven that these children have a greater risk of developing cerebral palsy, but the risk is now declining.
Assisted Reproductive Technology and Cerebral Palsy
Cerebral palsy results from brain damage during childbirth or abnormal brain development while in the womb. It affects motor functions and can cause or contribute to multiple symptoms and associated conditions.
An exact cause for abnormal brain development or brain damage cannot always be identified. However, there are many risk factors associated with cerebral palsy, including ART. Studies from ten to fifteen years ago proved that children born after ART have higher rates of cerebral palsy.
One study from 2010 looked at nearly 600,000 children born between 1995 and 2003. The researchers found that babies born after ART were twice as likely as naturally conceived babies to have cerebral palsy.
They concluded that the increased risk was associated with a higher incidence of twins and higher-order births with ART. ART also increases the risk of preterm births. When the researchers looked at singleton births after the use of ART, there was no increase in cerebral palsy risk. More than half of the ART births were twins or triplets, compared to just 7% of naturally conceived babies.
In vitro fertilization (IVF) has come under particular criticism for the high rate of twins, triplets, and even more. Multiples in birth raise the risk of complications as well as cerebral palsy. Multiple embryo transfers during IVF can lead to multiples.
Cerebral Palsy Risk Continues to Drop
More recent studies continue to show that children born after ART are still more likely to have cerebral palsy. However, the risk of CP has dropped over the last couple of decades. The rate of cerebral palsy in children born after ART is still higher, but the overall rate has dropped.
One study from 2023 found that the crude risk of cerebral palsy in children born using ART dropped from 0.9% to 0.3% from 1990 to 2010. The number of children born with CP after IVF dropped from 8.5 to just 2.8 per 1,000 live births.
One likely reason that CP has dropped among children born through IVF is that many parents now choose not to do multiple embryo transfers. Many parents choose to transfer just one embryo, even though there is a risk it will not turn into a viable pregnancy.
The current data show that the risk of cerebral palsy is approximately the same for twins born through IVF and twins conceived naturally. This proves that multiple births is a leading factor for CP because of the complications it can cause.
As ART becomes more advanced and safer and practices regarding the number of embryos transferred change, fewer children are born with cerebral palsy.
