Although we weren't in A territory yet when we had our kids, I can say that each baby and pregnancy brings on new feelings, and changes.
When I got pregnant with DS, it was planned, and happened immediately. It made us much closer, and stronger, he was totally into being a dad, went to all the dr visits with me, and was right there at delivery, and proud pappa. He didn't get however how I could love that new baby more than him right off the bat, but he eventually got it.
We had a lot of stress after he was born, and I went back to work, he worked regular day hours, and I did evenings. DS was a HORRIBLE AWFUL COLIKY baby, and H had him every evening all on his own, after working all day, and it was a lot for him. I was exhausted, because I got home from work at 11:30-12 and did the night duty, up every two hours for feedings, and so forth, it was tough. We pulled away a bit. But came right back together when life threw a road block up, we had to move away from family, back to relying on only each other. Those two years we lived away were good for us.
The second child brought it's own challenges, and changes, moving back home, a sick baby, new jobs, building a house....But we did ok.
I guess what I am trying to say is each baby changes things, and puts stressors on you, and your relationship, but if it's soemthing you want, and you make time to talk, and be with each other it can strengthen a relationship.