It is hard. Not everyone finds that a tight budget makes for tighter families. The most important thing is that you and your partner be honest with each other. When you have a baby, you're working through a lot of emotions anyway, and adding financial stress to everything else would have been too much for us. You'll also need to consider how marketable you'll be after a pause in your work life.
Some moms keep up by doing temp work or consulting.
For others, there's simply no way back. You can't freelance for the police department, and there's a long list of people waiting for jobs like mine. Most fields offer some middle ground, but it often takes effort to find it. I kept thinking of how I could shape my own career. Given the nature of organizing conventions, she was able to work part-time, evenings, and weekends once her oldest child turned 2.