Forcing a new mom to choose between spending time with her baby or going back to work is counterproductive. A year passes in a blink and a maternity leave of 12 months allows the mom to ensure that she and her baby are healthy. Childbirth is traumatic, just because it has been going on since the beginning of time does not mean it's not traumatic, so women should get a reasonable amount of time off.
No, United States should not adopt Serbia's maternity leave policy. The cost to employers and lost productivity in society would be enormous. Serbian salaries a fraction of those in the US, and the labor market for women is literally worlds apart. Comparing a tiny economy like Serbia with USA is truly an apples-and-oranges idea.
It would be wonderful to have a full year of paid maternity leave. However, this could be a huge expense for the government, so perhaps this amount of time could be shortened. Another option would be to have paid leave for 3-6 months, then require companies to provide paid leave for the next six months for employees who plan to return to the workforce.
The United States should not adopt Serbia's maternity policy, which calls for a full year of salary. Many companies cannot afford to pay this, so it should be up to each company. It would onerous from many. If voluntary, companies with more generous policies can use it to help attract higher skilled workers.