Colb then argues
Returning to the question of whether consensual intercourse represents "consent" to pregnancy, consider the factors identified above. Is an act of consensual sexual intercourse extremely risky with respect to pregnancy? The answer depends in part on the woman's age, on where she is in her menstrual cycle, and on whether she or her partner is using contraception.Let's leave aside pregnancies that result from an act of rape as those are clearly outside of any notion of consent.
Even if a woman has unprotected sex, however, her odds of conceiving are quite low (some estimates are of a 2% or 3% chance), and we do not ordinarily treat as "consent" the taking of such a low risk. Furthermore, the "odds" are complicated by the fact that many women - especially sexually active minors who have not received accurate and complete sex education - operate under misapprehensions about how likely they are to become pregnant, including the false beliefs that (a) pregnancy is impossible the first time, (b) withdrawal before ejaculation precludes conception, and (c) sex in positions other than the missionary protect against conception.
If one can be said to "consent" only by knowingly taking risks, it would seem in many cases to be inaccurate to say that a woman who has had consensual sex has thereby consented to nine months of pregnancy and labor.
A second factor we identified in considering the equation between risk and consent was the legitimacy and importance of the activity giving rise to the risk. If we believed, for example, that having sex is not an especially important part of life, then it might be acceptable to demand of women that if they do not want to endure the burdens of pregnancy, they should simply remain celibate. For the most part, however, people do not view celibacy as a feasible life alternative.
Though some individuals take vows of celibacy, most view sex as an integral and even essential part of life. Accordingly, it would seem draconian to treat intercourse as consent to pregnancy, to tell women - in essence - that they must forego any and all sexual intercourse unless they are prepared to undergo a pregnancy. As a morally legitimate, low-risk (vis-à-vis pregnancy) activity, intercourse is a poor candidate for the equation of risk with consent.
Colb seems to argue that even those who are voluntarily sedentary don't consent to the health risks of such a lifestyle. Fine, but there is a more apt discriminator at work here in the context of sex and pregnancy, and that is active versus passive risk-taking.
I will agree that a sedentary person does not consent to the risks of his choice, but that doesn't mean he is free from consequence. Yes, as Colb points out, our medical system will treat his sedentary related conditions, and in some circumstances we the taxpayers foot the bill (thanks to emergency rooms). However, that does not mean a person who has health insurance does not avoid the consequences of his choices, his payment is generally in funds and in other behaviors he generally abhors, i.e. going to the doctor or taking medications indefinitely.
Clearly the risks are passive for the health risks of a sedentary lifestyle. But when dealing with consensual sex, we are dealing with an active risk taking. Despite crude jokes by so-called comedians, sex is not a passive enterprise for any man or woman. And it is this active engagement, rather than some meager medical data or blanket assertion that sex is "a poor candidate for the equation of risk with consent."
On the contrary, it is equivalent or far more a candidate than other active risk/consent activities like skiing or driving. One could ski for years or drive recklessly for years and yet sustain no injury or injure someone else even though the risks are significant. Similarly, every time a man and a woman engage in intercourse, there is a non-zero chance of a pregnancy. A skiier or a driver can take precautions just as a sexually active woman can, but such precautions do not fully reduce the risk to zero. The only way to avoid the risks of sex, skiing or driving are to not engage in the actitivies. In this way, sex is an active risk activity and no matter how Colb tries to paint the activity in any other way, there are consequences that cannot be avoided simply because they are inconvenient.
The pseudo-scientific camoflage offered by Colb to justify that because in engaging in sex a woman is not actually consenting to the risks inherent in sex is bogus. All of the examples of risk-taking as consent are active pursuits, meaning a person takes an affirmative act to further those pursuits. Sex is a pursuit with a high degree of active invovlement and full of affirmative steps. Justifying the aborting of a pregnancy as a burden to which a woman did not consent even in the presence of consensual sex divorces an act from its reasonable consequences. Sex invites pregnancy and to attempt to divorce the two is ludicrous.