When I criticized Hobby Lobby for its attempts to evade the Obamacare contraceptive mandate, a friend of mine thoughtfully replied, “Lara, I don’t think the Hobby Lobby case has anything to do with the daily birth control pill — it is only dealing with not wanting to cover drugs and medical devices that actually “end” a pregnancy after an egg has been fertilized.” She wasn’t so ready to vilify Hobby Lobby for standing on its anti-abortion principles, a position which a substantial minority of Americans support.

Like my friend, I am willing to grant that Hobby Lobby may earnestly be trying to avoid funding what it perceives to be “abortions.” But what this discussion shows is that Hobby Lobby, and many people on both sides of the abortion debates, have been misled about how pregnancy works. And this has profound implications for how we think about contraceptives such as the IUD and the morning-after pill.

When we debate abortion, we talk about an abstract ideal of pregnancy. We imagine a conceptus that will either develop and become a full-term baby, or a conceptus that will be aborted. But in fact, most conceptions don’t end in either of those scenarios. As it turns out, only about 30% of conceptions survive to become babies, even when we do our best to preserve them. After conception, about 40% of blastocysts perish before implanting in the uterus, and another 30% of embryos and fetuses are lost after implantation, mostly in the first trimester.

As far as scientists currently understand, most of the 70% of conceptions that fail are beyond our control to preserve. They have the wrong number of chromosomes, or development goes wrong at some crucial moment, and they are therefore incompatible with life. At the margins, though, our actions and our environment can make some difference.

As women who are trying to have a baby are all too aware, there is scientific evidence that a host of everyday habits may raise one’s chance of miscarriage. Preconception and pregnancy guides contain seemingly endless lists of potential dangers: caffeine, lunch meats, alcohol, stress, sushi, kitty litter, hair dye, soft cheese, cigarettes, workplace chemicals, over-the-counter painkillers, nail salons, prescription drugs… the list goes on.

These dangers to wanted pregnancies apply to unintended ones as well. This means that there are going to be cases where a woman gets pregnant by accident, and miscarries because she gets sick from tainted lunch meat. All heterosexually active women of childbearing age are subject to this possibility. (Even those who are “active” because they are raped.) It would seem crazy to ask women of childbearing age to forgo all aspects of daily life that might marginally increase the chance of losing a pregnancy, whether that pregnancy was desired or not. It would seem even crazier to expect women to forgo lifesaving medical treatment, such as chemotherapy for cancer, because it could damage an unrecognized pregnancy.

Like prescription drugs and lunch meat, IUDs and morning-after pills are part of normal, daily life for many women. And like prescription drugs and lunch meat, they have a purpose unrelated to abortion. They may unintentionally cause occasional pregnancy losses, but that is not their intention or their primary function. It is a side effect. And there is no justification for penalizing contraceptives for this side effect if we are willing to accept cancer drugs, lunch meat, and hair dye.

Some historical perspective is helpful here. Before the twentieth century, doctors and women alike assumed that when pregnancies failed, it was because of one of a myriad of things that the pregnant woman must have done or encountered. It was a different list than the one bequeathed to us by What to Expect When You’re Expecting: it included strenuous wash days, fright from thunderstorms, reaching too high, pedaling a sewing machine, eating spicy food, breastfeeding an older baby (and on and on). But the length and breadth of the list certainly lived up to modern standards. One might imagine a scenario involving tremendous blame and mother-guilt.

But this wasn’t the case. Before the nineteenth century, lengthy lists of possible causes of miscarriage appeared to be assembled to explain the phenomenon, and perhaps give women a chance of preventing them in order to protect their health and fertility, not in order to assign blame for the loss of a child. Women and their doctors were fatalistic about childbearing in general, and about miscarriage in particular. At a time when it was hard to reliably preserve the lives of small children, and even adults, doctors might have had an interest in retrospectively explaining a pregnancy loss, but they did not generally mean to assign guilt.

In the nineteenth century, as American women’s rates of childbearing dropped dramatically, some doctors began accusing women of deliberately causing their miscarriages. Women and their husbands had grown less fatalistic about childbearing, determined to have smaller families. They were using withdrawal, douching, periodic abstinence, and sometimes procured abortions to have families with 3 or 4 children, instead of 7 or 8. While historian Shannon Wythecombe has found that nineteenth-century women continued to take a fatalistic attitude toward their miscarriages, rather than expressing guilt or accepting blame, anti-abortion doctors began to believe that all miscarriages should be regarded more-or-less as abortions.

Our current discussion of the contraceptive mandate unfortunately draws on this nineteenth-century legacy of suspicion and blame. If a woman is known to be using contraceptives, her pregnancy loss might be labeled an “abortion.” This makes it difficult for someone who personally abides by a pro-life position to feel comfortable using an IUD even if it is otherwise her best contraceptive choice, or even to use emergency contraception after she is raped.

We might be better off recognizing how valid some of the early modern fatalistic sensibility turned out to be. In fact, as far as we now understand, we have little control over preserving conceptions, and no foreseeable way to change this. And to the degree that we might have some control at the margins, to adhere to the many restrictions on a regular basis, aside from when we are actively trying to conceive, would require forgoing so much of what is good about daily life, it hardly seems like a reasonable expectation: no pet cats, no morning coffee, no glass of wine with dinner, no headache pills, no lifesaving chemotherapy, and no IUDs or morning-after pills.