Sen. Tammy Duckworth, D-Ill., is pregnant with her second child and is set to be the first ever senator to give birth while in office.

Duckworth broke the news to Lynn Sweet of the Chicago Sun-Times, telling the political columnist that she is six months along and, just six weeks shy of turning 50, that she felt "great" about motherhood and the demanding role of being a senator.

"As tough as it's been to juggle motherhood and the demands of being in the House and now the Senate, it's made me more committed to doing this job," she told Sweet.

With more than 20 female senators, the world's most deliberative body has had to change its traditional status as an old boy's club. Back in 2001, then-Sen. Kay Bailey Hutchison, R-Texas, adopted two children and was often seen in the hallways and sometimes just off the Senate floor with her baby.

Her colleagues were thrilled to hear Duckworth's news.

"When she told me several weeks ago that she and Bryan were expecting a new baby to join their little Abigail, I was speechless. I have learned to never underestimate Tammy Duckworth," Sen. Richard Durbin, D-Ill., said in a statement.

Duckworth's first child, Abigail, was born in late 2014. A few months later, while still on maternity leave, Duckworth decided to run for Senate.

Duckworth opened up to Sweet about her struggles to conceive again. "I've had multiple IVF cycles and a miscarriage trying to conceive again, so we're very grateful," she said.