Okay, once in a while I wish I could just sleep in, just be sick and have no one depending on me, just do what I want to do without having to consider someone else. But that thought just brings me to my other hand, my other thought. Motherhood IS a sacrifice. But let's think about what's being sacrificed.
In my list of things I sometimes wish, I find some pretty selfish wishes. Seems to be the only real sacrifice to be found in parenting is a sacrifice of self. But isn't that something we're supposed to be doing anyway? This life isn't about us. As Christians we are to live for Christ, reflect His image, die to self and let His life become our own. What a profound gift parenting is. What an opportunity for Christ to accomplish His work in us. What a blessed vehicle for us to be molded into Christ-likeness. It's a very rewarding way to do what we're supposed to be doing anyway: decrease so that He might increase.
My opinion is that it would probably be much more difficult to die to self if one didn't have children. I would likely be much more selfish than I am if I didn't have the constant reminder that it's not about me.
Therefore I urge you, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, which is your spiritual service of worship. And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect. Romans 12:1-2