Robillard’s idea was unconventional not only because it challenged the dogma of the time, but because it implied certain evolutionary consequences. It was the newness of paternal genetic material that, maybe, the mother hadn’t had enough exposure to before. The catalyst in these cases of preeclampsia, he eventually surmised, wasn’t the newness of pregnancy. “These women had changed the father,” he told me. But Robillard, now a neonatologist and epidemiologist at Centre Hospitalier Universitaire de La Réunion, on Réunion Island in the Indian Ocean, kept seeing the condition crop up during second, third, or fourth pregnancies-a pattern that a few other studies had documented, but had yet to fully explain. Preeclampsia, a pregnancy complication that causes some 500,000 fetal deaths and 70,000 maternal deaths around the world each year, had for decades been regarded as a condition most common among new mothers, whose bodies were mounting an inappropriate attack on a first baby. In the early 1990s, while studying preeclampsia in Guadeloupe, Pierre-Yves Robillard hit upon a realization that seemed to shake the foundations of his field.
