Researchers in Sweden found that there was a slight increased risk of cancer in children and young adults conceived by in vitro fertilization (IVF).

The study published online today in the Journal Pediatrics is the first study to find a link between IVF and cancer in children. The researchers followed almost 27,000 children born after IVF between 1982–2005 using the Swedish Cancer Register. They then compared the number of children who had cancer and were born after IVF with children who were not conceived by IVF.

The researchers discovered that a number of other factors such as age of the mother, smoking, and BMI (body mass index) of the mother did not significantly affect the cancer risk in offspring. However High birth weight, premature delivery, the presence of respiratory diagnoses, low Apgar score and IVF were risk factors for cancer.

The study identified 53 cases of cancer in children who were born after IVF against 38 expected cases: 18 of them with hematologic cancer (15 of them acute lymphoblastic leukemia), 17 with eye or central nervous system tumors, and 12 with other solid cancers. There were 6 cases of Langerhans histiocytosis against 1.0 expected. The total cancer risk estimate was 1.42.

The researchers conclude that the small elevated risk may be associated with pre-term birth and breathing problems at birth, both conditions associated with fertility treatment.

Source: PEDIATRICS (doi:10.1542/peds.2009-3225)