ON AND OFF THE AIR:
* Births are busting out all over as season-ending plot lines this spring.
Last week on NBC's "Cheers," for example, Sam and Rebecca (Ted Danson and Kirstie Alley) decided to make a baby together. And on ABC's "Life Goes On" last night, Libby (Patti Lupone) added another Thatcher to the cast.
Tonight on CBS' "Evening Shade" (at 8, Channel 11), Ava (Marilu Henner) finishes what she began last week at a banquet -- namely labor -- and much of the cast is in attendance.