(Wall Street Journal) – Wesley, a high-school algebra teacher in Dalton, Mass., has taken in more than 70 children for foster care over the years, some for just a night or two. Social workers sometimes woke her up, asking if they could bring over a baby right away. She adopted three of them, two girls and a boy, now ages 7, 12 and 14. Wesley, 40, tried to have her own baby through artificial insemination. When that didn’t work, she turned to in vitro fertilization.

She gave birth to a daughter in 2018. That left her with three embryos that went into cold storage with more than a million others kept by families in facilities around the U.S. IVF entails the extraction of eggs from a woman, and, because of advances, doctors are more likely than in the past to implant only one embryo at a time. Higher success rates—the procedure now accounts for an estimated 2% of U.S. births—leave more embryos unused. (Read More)