In the 1960s, in vitro fertilization (IVF) was an experimental technology to help infertile couples have a pregnancy. From the 1970 until today, IVF has become increasingly common. In fact, it now accounts for over five percent of all live births in the U.S. and other developed countries.
Parents who opt for IVF are aware of certain risks associated with IVF, like babies being born early or smaller than normal, and the possibility of a multiple birth. Most parents find these risks are acceptable. However, a risk that some studies found in 2005 and 2013 is more frightening and less acceptable. Could a baby born with IVF have an increased risk of childhood cancer?
The Link Between IVF and Childhood Cancer
In 2005, a review of 25 small studies found a 33 percent increased risk for the most common childhood cancers – white blood cell and neurological cancers – in children born through IVF. In 2013, another study found an 18 percent increased risk. Cancer is the leading cause of death in children under age 15. It affects up to two in 10,000 children.
All the studies said that the overall risk of childhood cancer was still small. They also said that they could not tell if the risk was due to IVF itself or some underlying cause of infertility, like the older age of mothers or a genetic factor. Still, the findings were frightening and had a chilling effect on doctors and couples involved in IVF.
Reassuring News From the Largest Ever Study on IVF and Childhood Cancer
In April 2019, a University of Minnesota study was published in the American Medical Society journal JAMA Pediatrics. This is the largest study to date looking at the link between IVF and the risk of childhood cancers. This study included 2.5 times the number of children used in all the other studies combined.
Over 275,000 children born through IVF were compared to over 2 million children born without IVF. The children were drawn form 14 U.S. states between 2004 and 2012 and were followed from birth to between ages five and six. Except for a very rare type of liver tumor, the researchers did not find any overall increased risk for childhood cancer in the IVF children compared to the normal pregnancy children. The researchers could not tell if the increased risk for the liver tumor is due to IVF or to some other risk associated with infertility.
This study is good news for parents who have used IVF or are considering the option of IVF. It suggests that common childhood cancers like cancers of the blood or nervous system are not more common after IVF. The risk for a cancerous liver tumor in a child may be higher after IVF, but would still be less than three in one million.
The authors of the study caution that they only followed children for up to six years, so there may still be some increased risk in older children. They conclude that children born through IVF should be followed for any risk of childhood cancer, but that parents can be reassured that most childhood cancers are not more frequent in their children.