This month marks 40 years since the birth of the first baby conceived through IVF, Louise Joy Brown. Since then, more than eight million babies have been born using the technique. Advances in IVF testing have improved outcomes for couples with infertility. But these advances are also spurring debate over what's called mosaic embryos, those with both normal and abnormal cells. Dr. Tara Narula reports on why some fertility experts are torn over whether mosaic embryos should be implanted.
