'Baby Mama' delivers $18.3 million at weekend box office

"Hopefully we'll do somewhere in the $40 million range," Fellman said.

It was the second straight weekend that has shown better revenue than the previous year, following four "down" weekends, Dergarabedian said. The weekend gross for the films measured was up 17 percent at $91 million.

For the year to date, however, box office revenue is down 2.7 percent at $2.59 billion, with attendance off 5.4 percent.

Still, the recent upswing is "the perfect lead-in to the start of the summer movie season" which gets under way next weekend with the debut of "Iron Man," Dergarabedian said.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Media By Numbers LLC.

1. "Baby Mama," $18.3 million.

2. "Harold & Kumar Escape from Guantanamo Bay," $14.6 million.

3. "The Forbidden Kingdom," $11.2 million.

4. "Forgetting Sarah Marshall," $11 million.

5. "Nim's Island," $4.5 million.

6. "Prom Night," $4.4 million.

7. "21," $4 million.

8. "88 Minutes," $3.6 million.

9. "Dr. Seuss' Horton Hears a Who!", $2.4 million.

10. "Deception," $2.2 million.