That's because Jenni—JWoww—announced her pregnancy with Roger (which pains me to refer to him by a single name as though he were as famous as Prince). That means, though, that Snooki, Pauly D and Jwoww now have or will have children. Yes, you read that right, but I'll still write it again, because it's bloody astonishing and makes me weep for the world. Jenni, Snooki and Pauly D have children.
That leaves Ronnie, Sammi, Vinny and Mike childless, which is probably for the best, unless you care about MTV's ratings 21 years from now.
And yes, I checked. Ronnie and Sammi are still dating.
[Screenshot via JenniFarley.com]