OVERSOLD: The Misleading Promise of I.V.F. for Women Over 40. “What the industry didn’t say is that the success rate for older women is consistently low. . . . It focused on the 20 percent of women who succeed, not the 80 percent failure rate. The industry avoided saying that the technology hasn’t worked for an estimated 20 million women globally during the last 40 years.”

If you really want kids, you should start younger. Considerably younger:

The doctor acknowledges the dilemma faced by women who seek higher education and want to become established in a career before attempting to start a family. And he realizes that “ideally pregnancy should also occur when they are settled with a life partner who will share the burden of raising offspring.”

Nonetheless, Dr. Sauer points out, the facts of biology are irrefutable. “Biologically speaking,” he wrote, “women are most fertile between the ages of 15 and 30.” Although from a career perspective, many are unwilling to start a family then, ages 35 to 45 represent the “terminal decline in normal fecundity,” as well as a greatly increased risk of producing eggs and embryos with chromosomal and other abnormalities.

Biology is a stubborn thing.