These days, "mom" is king. It was perhaps the most frequently used word at the Republican National Convention this past week, where Ann Romney, mother of five, said, "It's the moms of this nation . . . who really hold this country together." Paul Ryan said his mother is his role model, and Chris Christie all but called himself a mama's boy.

Republicans' efforts to woo women have become fever-pitch pandering as the party tries to undo damage from comments such as Rep. Todd Akin's remark that a "legitimate" rape victim can't get pregnant, and Pennsylvania Gov. Tom Corbett's advice to women who object to invasive ultrasounds before an abortion: "You just have to close your eyes."

But given the GOP's extreme antiabortion platform, which does not include exceptions for rape or incest, focusing on motherhood as a gateway to women's hearts and votes seems misguided. After all, no matter how many platitudes are thrown around, this is the party that wants motherhood not to be a choice, but to be enforced.

In a way, Republicans are reflecting American culture, which assumes that all women want to become mothers. And the best kind of woman - the best kind of mother - is portrayed as one who puts her maternal role above everything else.

In 2006, the term "pre-pregnant" was coined in a Washington Post story about a report from the Centers for Disease Control and Prevention recommending that all women of childbearing age care for their pre-conception health. The agency said all American women - from the time of their first menstrual period until menopause - should take folic acid supplements, not smoke, not "misuse" alcohol, maintain a healthy weight, refrain from drug use and avoid "high risk sexual behavior."

The CDC was asking women to behave as if they were already pregnant, even if they had no intention of conceiving in the near - or distant - future. For the ?rst time, a U.S. government institution was explicitly saying what social norms had always hinted at: All women, regardless of whether they have or want children, are moms-in-waiting.

Telling women that what is best for a pregnancy is automatically best for them defines motherhood as a woman prioritizing the needs of a child, real or hypothetical, over her own.

Rebecca Kukla, a professor of internal medicine and philosophy at Georgetown University and the author of "Mass Hysteria: Medicine, Culture, and Mothers' Bodies," said at a recent seminar, "Do lesbians, women who are carefully contracepting and not interested in having children, 13-year-olds, women done having kids, really want their bodies seen as prenatal, understood solely in terms of reproductive function?"

She noted that this assumption - that all women will be mothers - has led to a "pre-conception" health movement, which "treats the non-pregnant body as on its way to pregnancy."

Kukla told me that she experienced this when she once went to her doctor to get an antibiotic for a urinary tract infection, and he asked if she might be pregnant or could become pregnant. Yes, physicians have to ask to inoculate themselves against malpractice lawsuits. But Kukla's doctor wouldn't drop the issue and insisted on a weaker drug that would cause fewer complications during a pregnancy.

"Never mind that I'm a grown woman who is capable of using birth control and would have ended a pregnancy had I become pregnant," she said. "Because I . . . could become pregnant, I got this other, less effective drug."

This obsession with parenthood as a given doesn't match the reality of women's lives. In fact, most American women spend the majority of their lives trying not to get pregnant. According to the Guttmacher Institute, by the time a woman with two children is in her mid-40s, she will have spent only five years trying to become pregnant, being pregnant or in a postpartum period. So to avoid getting pregnant, she would have had to refrain from sex or use contraception for 25 years. That's a long part of life and a lot of effort to avoid parenthood.

Almost all American women who are sexually active use some form of birth control. The second most popular form after the pill? Sterilization. And now, more than ever, women are increasingly choosing forms of long-term contraception. Since 2005, the number of women using an intrauterine device has increased by a whopping 161 percent.

And a 2010 Pew Research Center study showed that the rate of American women who did not have children almost doubled since 1976. That's nearly one in ?ve women today.

Laura Scott, the author of "Two Is Enough: A Couple's Guide to Living Childless by Choice," says the No. 1 reason women give for not wanting children is that they don't want their lives to change. In a two-year study she conducted of child-free women - many prefer to call themselves "child-free" as opposed to "childless," since the latter implies an absence or void - 74 percent said they "had no desire to have a child, no maternal instinct."

The other reasons they gave: loving the relationship they were in "as it is," valuing their "freedom and independence," not wanting to take on "the responsibility of raising a child," a desire to focus "on my own interests, needs or goals," and wanting to accomplish "things in life that would be difficult to do if I was a parent."

"Parenting is no longer the default," Scott told me. "For a lot of people, it's no longer an assumption - it's a decision."

Yet the stigma remains. On Web forums for women without children (I have yet to see such a space for child-free men), the most talked-about topic is the need to constantly justify their decision. The criticisms are so common that the steady and predictable line of questioning is referred to as "breeder bingo." One contributor even made a bingo card with frequently heard lines, such as "The children are our future!" and "Don't you want to give your parents grandchildren?"

On one site, a woman from Virginia wrote that she mostly gets confused looks when she tells people that she doesn't want children. "I suppose it never occurred to them that having kids is a choice," she said.

It does seem odd that it's women without children who are most often questioned about their choice. After all, parenthood is the decision that brings another person into the world, whereas being child-free maintains the status quo.

And that's what Scott finds truly disturbing. She says she often speaks to women who say they didn't know they had a choice.

"I see this a lot - where women are feeling a lot of external pressure and not owning feelings of ambivalence around having children," she told me. "Many of these women end up profoundly unhappy."

Indeed, studies show that children who were unintended are raised differently than those who were planned - a disturbing situation, considering that a third of births in the United States are unplanned.

American culture can't seem to accept the fact that some women don't want to be mothers. Parenting is simply presented as something everyone - a woman especially - is supposed to do.

This expectation is in line with the antiabortion movement and the Republican ethos around women and motherhood. No matter what women actually want, parenthood is perceived as the best, and only, choice for them.

In his speech accepting the GOP presidential nomination Thursday night, Mitt Romney said of his wife: "I knew that her job as a mom was harder than mine. And I knew, without question, that her job as a mom was a lot more important than mine."

If we really value motherhood - and if it's such a tough, important job - it wouldn't be a given, but a proactive decision.

As the Republicans talk about how much they "love women" - as Ann Romney enthused Tuesday - let's remember that love isn't shown by force or coercion. It's based on respect.