I see [0] that it mandates 12 weeks of unpaid leave total -- for pregnancy, childbirth, and the first few weeks of caring for the baby -- which is not hugely generous; but it is something.
Note the requirements, which exclude a lot of people including employees of small businesses: "In order to be eligible for FMLA leave, an employee must have been at the business at least 12 months, and worked at least 1,250 hours over the past 12 months, and work at a location where the company employs 50 or more employees within 75 miles."
When my sister developed health complications caused by her pregnancy, she had to quit her job. She had no other choice. But even if she hadn't quit, she would not have been eligible for FMLA. Now she is going through a divorce, and since she has no income, I am helping to pay her living expenses. My family is definitely feeling the ripple effects of our inadequate maternity leave laws in the U.S. right now.
[0] http://en.wikipedia.org/wiki/Family_and_Medical_Leave_Act_of...