Officially, these episodes are supposed to be 17 and 18. Everyone else has been numbering them non-officially, counting "Niagra" as one episode, so I have no clue what to do.
NBC originally planned to air the hour-long episode over two weeks. They opted instead to move the delivery up a week and have a two-parter. Thankfully they did that, because the first half was simply terrible. In a sub-par season, the first half-hour resembled the season as a whole--the plot doesn't go anywhere and it's funny.
Pam spends the first episode waiting until midnight to go to the hospital while having contractions in intervals that warrant going to the hospital. Her excuse is that she can stay an extra night at the hospital. Everyone wants her to go the hospital, but since she won't, they distract her by doing the usual silly things. The gags weren't that bad, but I couldn't help but be bothered Pam's reluctance to go the hospital even though she is clearly in pain. Finally, she tells everyone she is scared of what may happen, but Jim convinces her everything is fine, and they arrive at the hospital safely.
The second episode is much better, consisting of loving moments between Jim and Pam and a several funny moments. There weren't any real laugh out loud scenes, but it was pleasant enough. The conflict revolves around the baby's inability to latch onto Pam's nipple. The baby does latch on after a while, but to everyone's horror, it's the other couple's baby. No one notices, and I'm sure they don't want anyone to know.
Michael's subplot as the father figure of Dunder-Mifflin takes a weird turn as he pairs up Erin and Kevin. Obviously it doesn't work, but the result is Andy asking out Erin. The awkward wait is over, and there can be more relationship awkwardness.
The baby probably won't impact the show other than making Pam and Jim tired. What needs major improvement is the corporate storyline. They're selling printers now, but who notices?