NEW YORK (AP) — Health officials are warning new moms about the potential dangers of taking pills made from their placenta, after an Oregon infant's infection was tied to the practice.

Trendy among some mothers, the practice of eating the placenta after giving birth is believed by some to help with postpartum depression, breast milk production and energy levels. It's taken off in the last decade, touted by some celebrity moms and promoted on the internet. Now tens of thousands of U.S. moms do it, according to a rough estimate by researchers at the University of Nevada, Las Vegas.

But in an unu...