Ditto for me, except that also goes for their toddler years, young kids, pre-teen and teenage years!
We made the decision even before we married that when we had bambino #1, I would retire. (yeah right!). I worked while he got his PhD, with #1 arriving about 9 months before he had completed it. (he says that REALLY motivated him to finish)
We never bought a new car til last year (after 25 yrs. of marriage), and our vacations were mostly spent with family instead of at resorts and theme parks, but our kids have never wanted for anything they ever needed. That's because we've tried to live within our means, and that means ONE INCOME! It just takes some planning to get yourself in an income bracket that can support you and a willingness to live within those means.