@JewishBride: Don’t lose heart–3 months was magical for us, we totally reconnected as husband and wife then. (If you don’t believe me, see the fact that I have a 7 month old and I’m 5 months pregnant.) Before that, it was all about survival mode.
To OP: Yes, of course it’s hard. Of course there are adjustments. But I don’t think our marriage took a nosedive at all. I love my Darling Husband in a totally different way now, and in all honesty, I think I’m happier now. (This is big for me to say, I obsessively wondered if having a baby would wreck our marriage.)
The most important things, are communication, clear expectations, and not keeping score. Just because you were up one night with the baby, doesn’t mean that you shouldn’t get up the next night if your partner just can’t pull it together.
Darling Husband was great about this, he did all of the middle of the night feedings every Friday and Saturday. Every single one. He reasoned that I deserved those two nights of uninterrupted sleep after being on baby duty all day. I did all night Sunday so he could be prepared for the work week. But Monday-Thursday we each did two, normally.
However, there were lots of nights when one of us would say “Let me grab the feedings tonight Honey, you look tired.” He shoved me out the door to get a Pedicure when she was two months old, even though I told him I didn’t want to go. When “Hunger Games” came out, Dirty Delete was a month old. We didn’t have a babysitter we trusted, so we alternated–DH walked the baby around the mall so I could see the movie first, and then the next day, I hung out with her at home so he could see it.
I could go on about this, but really, you just have to work at it. And if you turn on each other in the early days (and you probably will) let it go, because the only other person who knows how tired/stressed/overwhelmed you are is your partner.