This episode contains a lot of hospital-oriented drama, and in my opinion it has several beneficial lessons. Karen is unconscious in the hospital because she has a disease that causes her to have seizures. Lucas and all of his friends are there to support her, despite it being their last day as high school students. The doctors feel that it is best to perform a c-section on Karen so that the baby will be safe. Lucas has a baby sister! However, Karen has still not woken up. Lucas is going to skip graduation, and his friends say that they won't go if he doesn't. Eventually he decides to go, but I think the fact that his friends were going to stand by his side speaks volumes about the importance of loyalty.
Another good lesson in this episode occurs when Brook turns herself in for cheating on the calculus exam. She feels guilty for letting Rachel take the blame, and she decides that she has not earned the right to graduate. The principle appreciates her being honest, and understands that she will be going to school for fashion (not engineering), and so he decides to let both her and Rachel graduate. This shows that telling the truth is far better than lying and pointing fingers at others.
In this episode, Lucas and Nathan tell Dan to stay away from their families. Despite this, Dan goes to the hospital to see his newborn niece. After holding her, he goes to the police station (where he will turn himself in for Keith's murder in the next episode). This was very well constructed. One moment Dan is holding Keith's child in his hands, and it is as if he finally feels enough guilt to take the blame for his brother's death.
At the end of the episode, Hayley is giving her valedictorian speech when her water breaks (a bit cliche - having it break when she's on stage in front of everyone). No one acts strange about the fact that a graduating student is about to have a baby, perhaps because they know that Hayley isn't promiscuous. The fact that she is married and at the top of her class seems to make the teen pregnancy socially acceptable.