Children conceived through frozen embryo transfer had about twice the rate of childhood cancer seen in children conceived without fertility treatment, according to a large Danish study published Oct. 21 in JAMA. In absolute terms, the rate stayed low, at about 41 cancers per 100,000 children per year compared with about 18 in other children. The study found an association and cannot show that the procedure caused the cancers.
For families who used fertility treatment, the headline figure can sound alarming. But a rate of about 4 in 10,000 children per year means most of these children will never develop cancer. Outside experts urged caution in interpreting the results.
