WASHINGTON — Sen. Tammy Duckworth, D-Ill., on Monday gave birth to a daughter, Maile Pearl Bowlsbey, becoming the first sitting senator to have a baby while in office.

Duckworth, who turned 50 on March 12, is one of only 10 women in the history of the nation to give birth while in Congress, with the other babies born to members serving in the House.

This is the second child for Duckworth and her husband, Bryan Bowlsbey. Daughter Abigail was born Nov. 18, 2014, when Duckworth was 47 and in the House, representing a suburban Chicago congressional district.

Maile was born at 7:07 a.m. at the Virginia Hospital Center in Arlington, Virginia.

Duckworth had originally planned a cesarean birth at a hospital in Washington, but the plan suddenly changed when Maile arrived earlier than expected and the couple rushed to a hospital near where they were staying in the Washington suburbs.

“It was such a rapid delivery that there was no time for a C-section or even to get across the river to the GWU Hospital,” Duckworth Communications Director Ben Gash Garmisa told the Chicago Sun-Times.

Members of the Senate threw a baby shower for Duckworth on March 20 in the Capitol — men and women, Democrats and Republicans attended.

Duckworth said in a statement: “Bryan, Abigail and I couldn’t be happier to welcome little Maile Pearl as the newest addition to our family and we’re deeply honored that our good friend Senator Akaka was able to bless her name for us — his help in naming both of our daughters means he will always be with us.

“Pearl Bowlsbey Johnson was Bryan’s great Aunt, an Army Officer and a nurse who served during the Second World War. He spent many summer months with her while growing up, we feel her presence still and are grateful for her service to our nation during the most challenging of times.”

“We’re also so grateful for the love and support of our friends and family, as well as our wonderful medical teams for everything they’ve done to help us in our decades-long journey to complete our family.”

Duckworth spent part of her youth in Hawaii; former Sen. Daniel Akaka, D-Hawaii, the first native Hawaiian to serve in the Senate, died last week.

I interviewed Duckworth in January about her pregnancy and she told me getting pregnant a second time was “a struggle.” Her fertility specialist for both pregnancies is Dr. Edmond Confino at Northwestern’s Feinberg School of Medicine.

Duckworth told me then she and her husband had tried various fertilization methods over a period of years before Abigail was conceived through a form of in vitro fertilization. After Abigail’s cesarean birth, Duckworth had to wait 18 months to try again. “I’ve had multiple IVF cycles and a miscarriage trying to conceive again, so we’re very grateful,” she told me.

Duckworth, an Iraq war vet, lost her legs and shattered her right arm when her Black Hawk helicopter was shot down in Iraq on Nov. 12, 2004.

Duckworth will be sticking around Washington with her newborn so she can return to the Senate if there is a close vote and she is needed. Senate rules do not allow bringing children to the floor of the chamber. Duckworth has said this rule should be changed.

With the exceptions of Duckworth and Sen. Kirsten Gillibrand, D-N.Y., who had one of her two sons while in the House, the other women in the Senate who are mothers had their kids before entering Congress.

There are now a record 23 women in the Senate, with the newest member, Mississippi Republican Cindy Hyde-Smith, sworn-in on Monday afternoon by Vice President Michael Pence. Hyde-Smith was appointed to fill the remainder of the term of former Sen. Thad Cochran, R-Miss., who stepped down due to ill health.

Becoming a mother — one who commutes between Washington and Hoffman Estates — has influenced Duckworth’s legislative agenda.

On Monday, Duckworth said in her statement: “Parenthood isn’t just a women’s issue, it’s an economic issue and one that affects all parents — men and women alike,” the senator continued. “As tough as juggling the demands of motherhood and being a Senator can be, I’m hardly alone or unique as a working parent, and my children only make me more committed to doing my job and standing up for hardworking families everywhere.”

As I wrote in January, since Abigail was born, Duckworth has authored measures to make sure major airports offer places for breastfeeding mothers to pump milk; the military creates a uniform policy for giving personnel time to bond with their newborn and adopted babies; and to make sure student parents have on-campus child care.

She also is a sponsor or co-sponsor of bills dealing with affordable child care, paid parental leave and other infant and maternal health issues.

Mayor Rahm Emanuel said in a statement, “Congratulations Tammy Duckworth on the birth of your beautiful daughter! Senator Duckworth has served this state and country as a Lieutenant Colonel, a U.S. Representative and a Senator — but there is no higher rank than parent. Illinois is lucky to have a Senator who fights for our families, and Amy and I are thrilled to congratulate the Duckworth family on this blessed occasion.”

House Democratic Leader Nancy Pelosi, D-Calif., said in a tweet, “Congratulations, @SenDuckworth! Wishing the best to you, Bryan, Abigail & little Maile Pearl. I’m sure she will grow up to be just as strong as her mother!”

Gillibrand said in a tweet, “What a blessing! Welcome to the world, Maile Pearl. Wishing so much joy and happiness to @SenDuckworth, Bryan, and Abigail as they welcome their newest addition to the family.”

Sen. Amy Klobuchar, D-Minn., said in tweet, “Congratulations to my friend and colleague Tammy Duckworth and her husband Bryan and big sister Abigail on the new baby girl—Maile Pearl! Love the name and love her strength. She’s now the first woman in America to give birth while serving in the U.S. Senate!”

And Sen. Jeanne Shaheen, D-N.H., said in a tweet, “Congratulations, @SenDuckworth! We are all so excited for you, Bryan & Abigail. Welcome to the world, Maile Pearl – we can’t wait to meet you!”