The 49-year-old Democrat from Illinois stands to be the first senator to give birth during her term.
"Wanted to share some exciting personal news..." she tweeted, alongside a picture of two grownup ducks and a young duck joined by a plus sign to a baby duck, and a caption that read: "Duck, duck, duck...duckling!"
Wanted to share some exciting personal news... pic.twitter.com/ZZyu9pG2nq— Tammy Duckworth (@SenDuckworth) January 23, 2018
Duckworth told the Chicago Sun-Times she was expecting her second child, another girl, in April -- a few weeks after she turns 50.
"Bryan and I are thrilled that our family is getting a little bit bigger, and Abigail is ecstatic to welcome her baby sister home this spring," she added in a statement, referring to her husband and three-year-old daughter.
Ten members of Congress have given birth in office -- but they all belonged to the chamber's House of Representatives.
"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," the Sun-Times quoted her as saying.
She entered the House in 2012 and then the Senate in 2016, where she is one of the 100-strong chamber's 22 women.
Born in Thailand to a Thai mother and American father, she is the joint second Asian American woman to serve in the Senate, alongside Kamala Harris.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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