Nahomie’s story helps explain the enigma. She tried injectables, but she says they caused excess bleeding that frightened her. The clinic had little counseling to explain and reassure her, so she stopped after nine months.

A sexually transmitted infection at the time meant that she couldn’t use an IUD just then, and a doctor told her that the pill would be inappropriate because she has vascular problems. Reluctant to return to a clinic that seemed scornful of poor women, she drifted along with nothing.

A couple of babies later, her first husband left her, and her next husband wanted to have children with her, so she acquiesced. A few children later, she began to push back, but in Haiti’s social structure she felt she had to accede to her husband’s whims. “I asked to use condoms,” Nahomie said, “but he refused.” Last fall, shortly after she became pregnant with her 10th child, her husband ran off.

A book published a few years ago, “Reproducing Inequities,” notes that we are, painstakingly, learning what does work. The effective strategies go beyond the contraceptive devices themselves to include better counseling, more dignity for women in clinics, a greater choice of methods that are completely free  and a broad effort to raise the status of women.

The best way to elevate women, by far, is to educate girls and to give them opportunities to earn income through micro-loans, factory jobs or vocational training. It is sometimes said that the best contraceptive isn’t the pill or the IUD, but education for girls.

(A side note: Whenever I write about efforts to save children from malaria or diarrhea, I get cynical letters from neo-Malthusians who argue that saving children’s lives is pointless until birthrates drop. That’s incorrect. There’s abundant evidence that when parents are confident that their children will live, they will have fewer and invest more in each of them.)

In any case, the mounting academic evidence underscores what is intuitively obvious in Haiti: unless family planning is more successful in poor countries, they won’t be able to overcome poverty. “There’s no other way,” says Tania Patriota, the representative of the United Nations Population Fund in Haiti. “It’s indispensable.”

President Obama has already lifted the ban on aid for the Population Fund, and we now have an opportunity to lead a global effort to regain lost momentum for family planning. And while Nahomie’s story shows that this won’t be easy, it also underscores that there’s simply no alternative.