In 2010, the Dutch doctors decided to start treating babies born at 24 weeks instead of waiting until 25 weeks, and they studied what happened to these babies by 2 years old.
They looked at nearly a thousand babies born between 24 and 26 weeks, and found that about 66% survived to be 2 years old, with most doing okay and a few having more serious problems.
The study showed that treating babies born earlier didn't lead to a lot more severe problems, and that babies born at 26 weeks did better than those born at 24 weeks.