IVF won't up birth defect risk: Chinese study

Birth defect rates among children conceived with the help of IVF and other techniques are no higher than for the general population, according to the first large study to look at the issue among Chinese children.

Some research has raised concerns that children conceived through assisted reproductive technologies (ART) are more likely to have birth defects than children conceived naturally, Dr. Junhao Yan of Shandong University in Jinan and colleagues note in their report.

To investigate whether risks would be higher among Chinese children conceived with ART, the researchers gathered data from several different centers on 15,405 babies born between 2004 and 2008. Data on birth defects came from forms filled out by the doctor or nurse attending the birth.

There were 189 children in the group (1.23 percent) with serious birth defects, which the researchers defined as a problem that led to death or serious disability, not significantly different from the 1.35 percent seen in the general population.

Babies conceived through intracytoplasmic sperm injection, in which a single sperm is injected directly into an egg, had a 1.58 percent risk of having birth defects, compared to 1.11 percent for children born through in-vitro fertilization only. The difference was not statistically significant, meaning it could have been due to chance. However, the researchers point out that other studies have suggested an increased risk of birth defects with ICSI.

The researchers also found the same pattern of birth defects as seen in the general population, with heart defects, neurological defects, extra fingers or toes or fingers and toes fused together, cleft lip or palate, and digestive tract defects being the most common.

Freezing-a standard technique to preserve embryos after IVF-did not lead to increased rates of birth defects, the researchers found.

A French study out this year found around 4 percent of babies born via ART had major birth defects, not much higher than the rate seen among babies conceived naturally, by some measures.

According to the US Centers for Disease Control, one in every 33 babies born in the US, or about one-third of one percent, have a major birth defect.

SOURCE: Fertility and Sterility, published online September 16, 2010.