This is a source of considerable political and social discussion. The two main points of view can be described as thus:
1) Women are discriminated against for choosing to have children and society should force private enterprises to make allowances for childbearing. These typically include job protection, wage protection, child care, time off for birthing and pregnancy, and increased medical coverage.
2) Having children is a lifestyle choice as birth control and family planning are fully controllable by individuals. Nor should businesses be forced to pay wages and salaries to those that haven't earned them by putting forth the time and effort that others have done. Also, such desired benefits are an undue burden on companies with insufficient revenue to fully implement them, nor is it prudent for gender politics to be legislated to benefit the whims of a small, but vocal, lobbying group.
3) In Sociological terms the "mommy track" is the action of employers discouraging women from goals in the work force due to the responsibilities of being a mother (Curiel 2008, Chuck N. Brandon P.)