Firstly, the moral consideration is almost irrelevant here. Do laws reflect morality? No - and the abortion discussion is largely a legal discussion. That being said, the legal dimensions of abortion are very difficult. On the one hand, bodily autonomy must be considered. On the other hand, this is an organism that - especially in the later stages - is clearly a potential human being, and this has to be taken seriously.
Consider the following point. Let's say my mother, when pregnant with me, has a fight with some person, and that person punches her in the stomach, in such a way that my development is harmed and it impacts me when I have been born and grown. In such a case, I can later sue the person for damages to my person. Thus, the law clearly ascribes a degree of personhood to fetuses, for if I was decidedly not a person but a thing during my fetal stages, I would not be able to sue.
The difficult part is establishing exactly what this legal personhood entails, and therefore how the fetus ought to be treated at its various stages. Now, considering that it is illegal to kill a baby, I think it would be entirely inconsistent to not make abortion legal in let's say the last few weeks or so of pregnancy, during which time the baby is basically the same as it is when it comes out.
But there are some more relevant factors. Consider the uniqueness of the fetus-mother relationship. It is unprecedented legally, and it is therefore extremely exciting. It is a shared relationship; a true dependency of one organism over another, and the two occupy a shared space. Now, this has to be given due attention. A very fundamental legal principle is the idea of occupying a certain space - a person has to occupy a space. The fetus has to occupy this space. Thus, rejection of the fetus is expulsion from its place - this has interesting legal ramifications.
I have not fully composed my thoughts on this matter, but I just wanted to relate some of the considerations I've been thinking about. In the past I have felt myself drawn to the position you take, where the lives of babies are of less value than more intelligent animals. But I have found myself troubled by this moral analysis because it cannot make irrefutable claims about what to do, and it also clearly does not guide us in a legal analysis. Perhaps it is true that a mentally handicapped person or a baby is of less moral value than a pig, but even if this is true, it is not practically possible to be integrated into our legislation.
So as it stands, I think abortion is a very serious legal issue and should be permitted in most cases up until a certain stage of fetal development. As to what occurs after that point and what that point is, I have not yet fully worked out my thoughts.