Eggs unlimited

On 11 August 2014, an anonymous user of a popular infertility forum typed a message. “I am 47 years old and have been keeping an avid eye on the OvaScience website (they have three new treatments to be available over the next few years),” she wrote. “The treatments are to do with developing egg cell treatments to help the IVF procedure … Does anyone else have any information?”

In the 14 months since, respondents have flooded the forum with more than 3500 replies, many brimming with optimism about the company's promise. One poster writes that she is $300,000 in debt (“yes, that's right, not a typo”) from other fertility treatments. Still, she plans to borrow more for a shot at what OvaScience says it can do: coax primitive cells in the ovaries to turn into mature eggs. “I am betting my life that I will have a baby” with this technology, says another, who has liquidated her family's retirement plan in part to buy stock in the company.

OvaScience is preoccupied by an enduring mystery in human biology—why...