"Proceed with caution" traffic sign, against a blue sky.

News broke this week that the first “three-parent” baby had been born. But the untested and controversial nature of the procedure that created the child, and the end run around public policy that it entailed, raise many more questions than answers.

Combining reproductive tourism with high-risk experimental science, a New York-based American doctor, John Zhang, took a Jordanian couple, who wish to remain anonymous, to Mexico, in order to avoid U.S. oversight. The baby’s birth occurred on April 6, and was reported by New Scientist on September 27.

First, let us hope the child is and remains as healthy as the announcement says he is. There are, however, reasons to be concerned.

This happened in Mexico because, said Zhang, there are “no rules” there. It may not be technically illegal in the U.S. unless public funds are involved, but Congress has blocked the Food and Drug Administration from authorizing clinical trials. The FDA itself considered the safety of the procedure in 2014 and decided then that “there is not enough data either in animals or in vitro to move on...