Meeting your argument on its own ground raises an interesting point. If a pregnancy is reducible to a mere "biological contingency"--just another lifestyle choice--then what of a man's rights vis a vis an "avoidable biological contingency" that *he* wants no part of? I'm not suggesting he ought to be able to compel a woman to abort a pregnancy (or carry it to term); that is clearly an unreasonable invasion. But by your standard--a life free of "gender-specific burdens"--shouldn't he be able to legally renounce his interest in, and responsibility for, any child issuing from a pregnancy unwanted by him? The financial and emotional responsibilities of fatherhood being a gender-specific burden and all.