1. Your Life Will Never Be The Same
You've been warned and will likely be warned again every single step of the way. Deciding to have children means your life will never be the same and this is also true for your marriage.

Adding new people to the world who you care about with all your heart means your priorities and perspectives are going to change beyond what anyone can explain to you. When it comes to your marriage, new dreams will arise and old ones will be let go, and that's simply part of the journey. 

You'll also find new identities as parents and will have to learn to embrace these changes in yourself and in your partner. With any luck, this will make you stronger and more bonded than ever before.