A few months ago, “Modern Family” star Sofia Vergara’s dispute with her ex-fiance Nick Loeb over what to do with their frozen embryos became public. The two used in vitro fertilization to create embryos. But when they split, Vergara wanted keep the embryos frozen, while Loeb wanted them as children. The disagreement highlights the complicated moral and legal questions that families, doctors and courts are facing as the number of frozen embryos in fertility clinics across the country grows. We look at what families are doing with unused embryos.