Children born after use of assisted reproduction technology do not have an increased risk for any cancer, but those born after frozen-thawed embryo transfer have an increased risk for childhood cancer, according to a study published online 1 September in PLOS Medicine.

Nona Sargisian, from Sahlgrenska University Hospital in Gothenburg, Sweden, and colleagues conducted a registry-based cohort study using data from Denmark, Finland, Norway and Sweden involving 7,944,248 children, of whom 2.2% were born after use of assisted reproduction technology (ART).

The rates of any cancer and specific cancer groups were assessed for children born after each conception method.

The researchers found that after a mean follow-up of 9.9 and 12.5 years, the incidence rate of cancer before age 18 years was 19.3 and 16.7 per 100,000 person-years for children born after ART and spontaneous conception, respectively (adjusted hazard ratio, 1.08; 95% confidence interval, 0.96 to 1.21; P = 0.18).