This machine could keep a baby alive outside the womb. How will the world decide to use it?

Beth Schafer lay in a hospital bed, bracing for the birth of her son. The first contractions rippled through her body before she felt remotely ready. She knew, with a mother’s pit-of-the-stomach intuition, that her baby was not ready either.

At just 23 weeks of gestation, her son teetered on the cliff edge of viability, the fragile threshold where modern medicine offers any promise of keeping babies alive.

Beth’s son did not – could not – cry when he was born. The instant his entire body, small enough to cradle in a single palm, landed in the delivering doctor’s latexed hand, a swarm of blue scrubs closed in to begin resuscitation. But despite their fervent attempts to triage, to coax air into his tiny, caved-in lungs, they could not supply what Beth’s son needed most: more time in the womb.

Beth is a 39-year-old painter turned graphic designer whose round frames and dark, frenzied bangs give her the look of an art student who never outgrew the studio. She will make you a mug of tea before you think to...