
Apparently some of the Losties have a mild case of OCD, drawing comfort from repeating the same things over and over. If that sounds a bit harsh, watch Maternity Leave a few times in a row and you'll never want to hear, see, or think about a baby ever again.
The episode does have a bit of a twist, however. Everything you see happens on the island, including the flashbacks which gradually come back to Claire through hypnosis and other convenient literary devices. The reason she's desperate to remember: Aaron is sick and Danielle's convinced it's "the sickness".
Danielle, Kate, and Claire make an interesting E-team (E for estrogen) on one of the few all-female jungle journeys. Claire eventually finds the abandoned Staff station, which is so bare and uninteresting it's actually creepy. Luckily her flashbacks fill in the gaps, showing what happened when Claire was abducted in Season 1. Ethan kept her doped up, Alex kept her safe, and Tom Friendly kept her out of earshot. She got a couple knitted booties out of the deal, though.
It's frustrating that they return from the Staff empty-handed but I suppose there were a few accomplishments. Danielle gains hope in finding Alex, Kate finds clues that the Others aren't primitive savages, and the Staff location is no longer a secret.
Henry Gale starts to ratchet up his campaign of manipulation. The wedge between Locke and Jack was already there, Gale's just starting to apply pressure to it.

Emilie de Ravin is indeed talented but there are situations where she just doesn't seem comfortable. Sharing a bunch of scenes with Evangeline Lilly doesn't do her any favors either, for Lilly is far and away the better actor. I can't help but wonder if de Ravin was thinking the same thing as most of the audience at this point: for the love of God, give her something interesting to do that's not 100% focused on her baby.
As noted above, Lilly puts in another terrific performance considering the material she's given. Even with Danielle "Rambo" Rousseau leading the way, was there ever any doubt that Kate was the one running the show?
I can't imagine anyone playing the role of Danielle except Mira Furlan. The look of despair in her eyes and the lines in her face drive home the fact that she's been to Hell and back.
William Mapother is God-awful and I lament the fact that he had so many speaking lines in this episode. He's especially terrible in the scene where he takes Claire to the tree stump outside the Staff. You know it's bad when Emilie carries the scene and almost seems Emmy-worthy in comparison.

The flashback sequences are comprised of a teeth-shattering alarm-type noise and then a quick succession of uncomfortable images. It's a pretty jarring experience each and every time and I suppose that's the point.
As nondescript as the Staff was, the E-team's descent into the station was very foreboding. Flickering flourescent lights tend to have that effect, especially when there are hints lying around that the station was recently in use.
Bonus points for good location selections in the jungle, particularly during the E-team journey.

The phrase "repeated viewings" and Maternity Leave simply do not mix, and that's really saying something considering my hopeless crush on Emilie de Ravin. Any character based on heavy repetition — whether it's Sawyer and his scowls, Michael and his shouts for Walt, or Claire and her tearful concerns over her baby — get a free pass for Season 1. But once we're deep into Season 2 and they're still doing those things, the needle starts to move on the Irritation Meter.
To be fair, there is the obvious significance of discovering the Staff station, which would come back into play with later arcs involving Juliet and Sun.

Maybe I need to be a mother before I can fully appreciate the agony Claire went through, but I've seen plenty of LOST fans (male and female) share the sentiment that her routine was getting quite old. But despite all that, I will say her final scene with Aaron (where she told him they were meant to take care of each other) was a very touching moment.
The atmosphere of Maternity Leave begins and ends with the abandoned Staff station, thanks again to the directing and photography. Even as the E-team were miles into their journey I never really got the sense that they were in any real danger.