Poehler, 38, who married the Arrested Development star in August 2003 -- previously welcomed son Archie in October 2008.
"I've been very lucky," Poehler told People at the time. "I’m feeling good, and I’m just overwhelmed with blessings."
Poehler will be back for a third season of NBC's "Parks & Recreation." the early season three pickup was designed to accommodate Amy's pregnancy.
"It will not affect the show," a source told E! Online in March. "They will take a short break and then resume production."