A study completed by Colorado's National Institute of Environmental Health Sciences (CNIEHS) shows possible evidence that women who are pregnant who live near fracking stations may be up to thirty times more likely to give birth to a child with congenital heart defects.
Because it is not yet a justifiable fact, and perhaps years of more studies will likely have to be completed before a correlation with be accepted, the industry says that they have been conducting their own studies for more than a decade and that there is no real association with fracking and birth defects, but that it is instead just a "terrible coincidence." CNIEHS decided that because none of the industry's studies look into data on birth defects from fracking, that it would provide its own study to the public. It has become a political arguing point, with extremes on both sides vehemently confirming and denying correlation and causation.
However, to look at the pure facts of the matter may do everyone well. Exposure to dangerous chemicals over a long period of time is detrimental to our health; just as exposure to too much sun over a period of time can cause sunburn and melanoma. While fracking certainly has been a good thing for our economy, there are currently 15 million people who live within at least one mile of a fracking well. In order to extract the goods, a well is dug near to an underground deposit and a mixture of sand, water, and chemicals is pump at a rate of high pressure to loosen the earth around the deposit and release the gas.
What it basically comes down to is a question of whether or not the 700+ chemicals that are used in the fracking process can cause harm to people and their unborn children. There have been other studies done on a smaller scale that back CNIEHS's claims, but the industry claims that the CNIEHS's study was already done on too small of a scale and is therefore unfounded.
What is known for sure is that prolonged exposure to chemicals like benzene, xylene, and toluene have been known to cause cancerous and benign tumors and other mutations in people. The studies assume that if those chemicals can be harmful to people, then they can also affect an unborn fetus. While the industry maintains that this cannot yet be proven, it certainly doesn't seem too farfetched.
Source: The Week, "Study: Living near a fracking well may increase the risk of birth defects" 3 February 2014