One of the resolves I had a bit of a discussion over was "Abortion violates a man's rights." The argument was that since men and women are equally complicit in conception, men should have their say in abortion considerations. The two faces of the issue are the cases where a woman might abort a fetus that would develop into a child the man wanted, and cases where a woman might bring to term a fetus that the man didn't want, which he would them be financially responsible for.
In the first case, I should think it is fairly obvious that forcing pregnancy and childbirth on women is unethical and amounts to slavery.
In the second, the situation is a bit more complicated. It is true that forcing fathers to provide financial support to unwanted children is imposing a burden on them against their will. At the same time, it is clear that in a world without abortion as an option, these men would be financially responsible, even for accidental pregnancies. So in World A, with no abortion, a man must pay for children he conceives, regardless of if he intended to conceive them or wants them. In World B, with abortion, the question is whether this availability means that a man can absolve himself of this responsibility because the birth of the child is contingent on the mother choosing to have it, even against his will.
I would argue that the availability of abortion changes nothing. There are many, many ways in which a man can avoid unwanted children; they are all contraceptive. Women also have many ways; contraception, but also abortion. It is not "unfair" that women get to make a choice concerning their own bodies while men don't. Men get full control of their own bodies, as do women. If fetuses gestated in external pods, the decision would be equal, but they don't: they gestate inside women. If you are a man and take all reasonable precautions to avoid pregnancy but a woman gets pregnant despite them, you are responsible for the resulting child, but for the nine months it is a part of the woman's body, she has sovereign control over it.