When frozen embryos are used during in vitro fertilization (IVF), the resulting children have a slightly higher risk than other kids for certain types of cancer, evidence from Denmark suggests, according to Reuters.
Analyzing health records of more than a million Danish children, researchers found that babies conceived through assisted reproduction involving frozen embryo transfer were more than twice as likely to develop childhood cancer, particularly leukemia and neuroblastoma, a type of brain cancer, according to the report in JAMA.
“We did not find increased risks with other types of fertility treatments,” said study leader Marie Hargreave of The Danish Cancer Society Research Center, in Cophenhagen.
Hargreave called for more research to validate her group’s findings. Moreover, “it is important to stress the fact that the increased risk is very small for the individual as childhood cancer is very rare,” she said in an email.
Denmark has one of the highest rates of assisted reproduction technology in the world. In 2018, 9.8% of newborns there had been conceived with fertility treatments, the researchers note in their report.