When my wife, Elizabeth, was pregnant, she had a routine ultrasound exam, and I was astonished by the images. The baby’s ears, his tiny lips, the lenses of his eyes and even the feathery, fluttering valves in his heart were as crisp and clear as the muscles and tendons in a Leonardo da Vinci drawing. Months before he was born, we were already squabbling about whom he looked like. Mostly, though, we were relieved; everything seemed to be fine.
Elizabeth was 40, and we knew about all the things that can go wrong in the children of older mothers. We worried about Down syndrome, which is more common in the offspring of older women. Elizabeth had the tests to rule out Down syndrome and a few other genetic abnormalities. That was no guarantee the baby would be okay, but the results were reassuring to us.