In the season 3 episode Nanny From Hell, Jeff tells Larry that Susie is pregnant, so Larry tries to persuade the Greenes to hire a nanny that he knows. The pregnancy never gets mentioned after that episode, as far as I can tell. Did I miss something?
Susie Greene's pregnancy is referred to, obliquely, in just one subsequent episode. The actress, Susie Essman, described the situation in an interview for Something Jewish:
The studded shirts episode was "Ben's Birthday Party" from season 4 (since the pregnancy was mentioned in season 3, not season 2 as the interviewer thought). Her line was