Do Babies Set Off a Marital Explosion?

Currently working the publicity circuit for her new movie, Julie & Julia, writer Nora Ephron was quoted in a piece for Parenting about how having children affected her marriage.
The mother of two sons once said:

When you have a baby, you set off an explosion in your marriage, and when the dust settles, your marriage is different from what it was.

Did you and your spouse endure this after entering parenthood?