According to the study's lead author, childhood cancer is considered rare and the increase seen is small to moderate, potentially linked to the infertility, said WebMD. "There is an increased risk for cancer in children born via IVF, but it's rather small," researcher Bengt Kallen, MD, PhD, a retired professor of embryology and head of the Tornblad Institute, University of Lund, Lund, Germany, told WebMD. "The estimate that we give is that the risk increases 40 percent, but the estimate has, of course, a degree of uncertainty," Dr. Kallen added. The study appears in the journal Pediatrics.
The team researched 26,692 Swedish children born via IVF from 1982 to 2005, using the Swedish Cancer Registry, said WebMD. The group compared the IVF children who had cancer versus those conceived naturally, noted WebMD, which added that the emerging study compliments information from a prior study by the same team, which looked at some 17,000 children. The prior study showed the same results; however, the emerging study indicates a stronger link.
After accounting for a series of variables - maternal age, pregnancy instances, miscarriages, body mass index - 53 cases of cancer were seen in the IVF children, an increase over the 38 that would have been statistically probable in the general population, said WebMD. Cancers included leukemia and cancers of the central nervous system and eye, as well as other solid tumors and Langerhans histiocytosis, a condition in which the body experiences an excess of a specific white blood cell, wrote WebMD. While experts disagree on this condition being a cancer, when the incidences of this condition - six cases - were removed, there still existed an increased risk of 34 percent, added WebMD.
IVF babies were 1.4 times - 40 percent - likelier to experience cancer in the follow-up period, which ended in 2006, said WebMD.
Last month we wrote that the risk of birth defects seems to be twice as high in babies conceived via fertility treatment, versus babies conceived naturally, according to French scientists. Assisted reproductive technology (ART) treatment includes a variety of infertility treatment methods such as vitro fertilization (IVF) in which an egg is fertilized by sperm in a lab, and intracytoplasmic sperm injection (ICSI).
Earlier this year we wrote, citing Reuters, that women who undergo IVF or ICSI and who become pregnant, experience an increased risk of giving birth to a stillborn baby, according to Danish scientists. In 2008, we wrote that Chinese researchers reported that the use of IVF or ICSI to conceive appears to increase the odds of Y-chromosome defects or "microdeletions" in male offspring, meaning that chromosomal defects, or deletions, could result in defective sperm production and possibly hypospadias, a congenital malformation of the male sex organs in which the urinary outlet, or urethra, does not open through the glans of the penis, but develops on the penis' underside.