As Jenny lay on the obstetrician’s examination table, she was grateful that the ultrasound tech had turned off the overhead screen. She didn’t want to see the two shadows floating inside her. Since making her decision, she had tried hard not to think about them, though she could often think of little else. She was 45 and pregnant after six years of fertility bills, ovulation injections, donor eggs and disappointment — and yet here she was, 14 weeks into her pregnancy, choosing to extinguish one of two healthy fetuses, almost as if having half an abortion. As the doctor inserted the needle into Jenny’s abdomen, aiming at one of the fetuses, Jenny tried not to flinch, caught between intense relief and intense guilt…

For all its successes, reproductive medicine has produced a paradox: in creating life where none seemed possible, doctors often generate more fetuses than they intend. In the mid-1980s, they devised an escape hatch to deal with these megapregnancies, terminating all but two or three fetuses to lower the risks to women and the babies they took home. But what began as an intervention for extreme medical circumstances has quietly become an option for women carrying twins. With that, pregnancy reduction shifted from a medical decision to an ethical dilemma. As science allows us to intervene more than ever at the beginning and the end of life, it outruns our ability to reach a new moral equilibrium. We still have to work out just how far we’re willing to go to construct the lives we want.

Jenny’s decision to reduce twins to a single fetus was never really in doubt. The idea of managing two infants at this point in her life terrified her. She and her husband already had grade-school-age children, and she took pride in being a good mother. She felt that twins would soak up everything she had to give, leaving nothing for her older children. Even the twins would be robbed, because, at best, she could give each one only half of her attention and, she feared, only half of her love. Jenny desperately wanted another child, but not at the risk of becoming a second-rate parent. “This is bad, but it’s not anywhere as bad as neglecting your child or not giving everything you can to the children you have,” she told me, referring to the reduction. She and her husband worked out this moral calculation on their own, and they intend to never tell anyone about it. Jenny is certain that no one, not even her closest friends, would understand, and she doesn’t want to be the object of their curiosity or feel the sting of their judgment.

This secrecy is common among women undergoing reduction to a singleton.