When the Choice to Be Childless Is Not Your Own

Since in vitro fertilization was invented nearly 50 years ago, at least 10 million children who would not otherwise exist have been brought into the world. New constellations of families — older moms, same-sex parents, single dads — have flourished. This is one of the major scientific success stories of modern life. But despite these advances, I.V.F. in the United States today is far from a sure path to parenthood. Fertility care is still so unevenly available that it feels almost like entering a lottery, in which the state you call home, the company that employs you or your relationship status determines whether you become a parent.

Access to fertility care is not a niche problem. The ranks of the infertile, already estimated at one in six people of reproductive age globally, are poised to grow: One recent study estimated that as more women worldwide age and delay childbearing, infertility cases among women over 35 will increase by nearly 50 percent by 2036.

In the United States the rising number of births to women over 40masks the fact that...