HARI SREENIVASAN, PBS NEWSHOUR WEEKEND ANCHOR: Since the 1980s, millions of American women have used fertility treatments, including the implantation of embryos, to become pregnant. But the process is expensive, averaging $12,000.

Earlier this month, "Reveal", part of the Center for Investigative Reporting, took an in-depth look at why the success rate might not be the best way of measuring a clinic and how the growth in IVF treatment has helped drive up America's twin birth rate by 75 percent since 1980.

For more in this story, I recently spoke to "Reveal" reporter Bernice Yeung.

First of all, you pick out a very, very tragic case and you follow that through. But it starts to highlight a much bigger picture that transcends the case in point, that there really isn't a great way for a consumer to judge where to go to get this treatment.

BERNICE YEUNG, REVEAL REPORTER: My partner and I, Jonathan Jones, spent a year looking at the fertility field, and what really struck was that there's a patch work of regulations that oversee the fertility business. It's basically regulated like other fields of medicine, which means it's pretty hands-off. But at the same time, given the ethical and innovation components to IVF and other fertility treatments, we just found that there wasn't a lot of information provided to consumers.

SREENIVASAN: So, give me an example here. What is a — if I went to a website to try to compare whether or not this is a good doctor or this is a good clinic, what do I have access to and what am I judging them based on?

YEUNG: The only legislation and regulation out there that explicitly deals with the fertility field is a law that requires the Centers for Disease Control and Prevention to collect success rates for IVF clinics. What we found in our investigation was that these success rates can be manipulated and they can also be really easily misunderstood by patients.

SREENIVASAN: You have a chart inside the story that looks at how often U.S. IVF clinic transfers more than one embryo and it's startling. Considering the CDC says and suggests that you should do one at a time, the number of clinics who actually just never do more than one at a time is the minority by a long shot.

YEUNG: I think 63 clinics in the United States do zero single embryo transfers in women who are their youngest group. This is a conversation that you need to have with your physician. It shouldn't just be an assumption that, you know, more than one embryo means success. There are now new technologies that allow for one embryo at a time over severalty cycles and success is just as possible.

SREENIVASAN: So, what's the incentive for a physician or a clinic to try to implant more than one embryo at a time?

YEUNG: Doctors and clinics are incentivized in the way that the data is gathered currently by the CDC to transfer more than one embryo at a time because it's true that using more than one embryo at a time increases your chances of success, but you can retrieve those eggs, develop them into embryos and then freeze those that you don't use the first time, and have similar chance of success, but also, experience less potential risk for the mother and for the baby, because there's this less chance of multiple gestation which is affiliated with a number of health and medical issues.

SREENIVASAN: From the "Reveal" which is in the Center for Investigative Reporting — Bernice Yeung, thanks so much.

YEUNG: Thank you.