The 14th Amendment says that no state shall "deprive any person of life, liberty, or property, without due process of law." The idea is that the unborn have rights too but I see trying to make this argument leading to a slippery slope of unintended consequences.
The idea is to protect the unborn but you know that it is more likely that some in government would use it to exercise more control over the "born". Using such an argument you would have some in government taking away children from parents who smoke cigarettes under the guise of protecting the child's life. Same too for parents who refuse to get children inoculated. What about parents of obese children? Shouldn't the government step in and take the child since the parents obviously aren't providing the child with a healthy diet and thus reducing the child's life expectancy?
Slippery slope and unintended consequences.