(RxWiki News) Roughly one percent of the 4 million children born in the U.S. every year are conceived through in vitro fertilization (IVF). According to the CDC, just over 47,000 IVF children were born in 2010.
Researchers have found a link between drugs used to stimulate the ovaries and higher risks of leukemia in the children born to women who have used fertility treatments.
While disturbing, it should be noted that the risk of any child developing leukemia is quite low.
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A research team of French scientists was led by Dr. Jeremie Rudant, from the Centre for Research in Epidemiology and Population Health at the National Institute of Health and Medical Research in Paris.
Dr. Rudant said, "It has always been hypothesized that assisted reproductive technologies may be involved in the onset of childhood cancer as they involve repeated treatment at the time of conception and or manipulation of the sperm and egg. And it is now established that a majority of acute leukemia have a pre-natal (pre-birth) origin."
Ovarian stimulation drugs, which are marketed under a number of brand names, do one of two things - stimulate hormones in the brain to release an egg, or stimulate the ovary to produce egg(s).
For this study, the research team studied the records of nearly 2,500 French children and their mothers. A total of 764 children had been diagnosed with leukemia and 1,681 did not have the disease. Mothers were asked about their conception history and any fertility treatments they had reviewed.
Researchers found that women who used drugs to stimulate ovarian function before they had other fertility treatments had more than double (2.6) the risk of having a child who developed acute lymphoblastic leukemia (ALL). The children of women who had used IVF also had a 2.3 fold risk of developing a rare cancer, acute myeloid leukemia that is seen in 500 children a year.
ALL is the most common childhood cancer, affecting some 2,000 youngsters under the age of 20 every year in the U.S. It develops mostly in the first two years of life, and the outlook is quite good. The vast majority (83 percent) of children are alive five years after diagnosis.
These numbers let you know that the absolute risk of a child developing ALL is 0.00005. Therefore, IVF babies have an absolute risk of 0.00013 of developing the disease.
"Previous studies have suggested a link between infertility treatments and acute childhood leukemia, but there haven't been many studies, most of them have been small, and they focused either on IVF or hormonal treatment," Dr. Rudant said. "Our study was much larger, and it's the first time that a specific increased risk linked to fertility drugs has been found."
Additional study is needed to learn more about this apparent link.
Results from this study were presented at the Childhood Cancer 2012 conference, hosted by the charity Children with Cancer UK.
All research is considered preliminary before it's published in a peer-reviewed journal.